>/. NATURAL RESOURCES ILLINOIS STATE LABORATORY OF NATURAL HISTORY | LIBRARY XI B RAR.Y OF THL UN IVLR.SITY OF ILLINOIS NATURAL HISTORY SURVE' 5&O.5 FB ^^. \A FIELD COLUMBIAN MUSEUM. PUBLICATION 118. BOTANICAL SERIES. VOL. II, No. 5. FLORA OF THE SAND KEYS OF FLORIDA BY CHARLES FREDERICK MILLSPAUGH, Curator, Department of Botany. CHICAGO, U. S. A. February, 1907. a. Mar. 11, 1907. FLORA OF THE SAND KEYS OF FLORIDA CHARLES F. MILLSPAUGH Mr. O. E. Lansing, Jr., having been commissioned by the Museum to make a botanical examination of all those islets lying to the west- ward of Key West, Florida, arrived at the City of Key West on the twenty-seventh of February, 1904, and, while making arrangements there for his work on the sand keys, collected a series of the plants of the island. Later he succeeded in commissioning a small sloop, in which he visited Marquesas "A" and "C" on March roth; "B" and "D" on March lith; "E," "F," "G," "H," "I,"on March 1 2th; Boca Grande, Ballast and Man Keys on March i3th; Key C, Woman Key, Key B, Archer's Key, and the small keys north and west of Woman Key on the i4th; and Mule, Cottrell, Mullet and East and West Crawfish Keys on the isth. Returning to Key West, and gaining passage on the U. S. Lighthouse Tender, he reached Fort Jefferson, in the Tortugas. From this garrison, as a base, he worked Bird and Loggerhead Keys on March ipth; Sand (or Hospital) and East Keys on the 2ist; and concluded his work in an investigation of Garden Key on the 22d. Mr. Lansing faithfully carried out his instructions, making a thorough investigation of each islet, during which he collected every species he saw on each no matter how well known to him nor how common its occurrence might be. These collections, together with his ^comprehensive notes and maps made on the spot, form the basis of the detailed consideration of the islets in the following pages. As was to be expected, this archipelago proves to be vegetated with only the usual broad strand species common to similar situations on the Antillean islands in general. The principal value of this survey lies, therefore, first: in the historical record of the present flora, which should enable future students to determine what species have come to the different islands since 1904, and what have been unable to sur- vive; second: in the knowledge of what species come first to such 191 192 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. microcosms, thus forming a basis upon which to judge of the ease or difficulty of dispersion exhibited by certain species; and third: how, and in what conformation, species spread when brought into an untainted environment, thus establishing a datum point for the possible solution of many problems in plant dissemination, as well as those relating to the property inherent in certain plants to maintain their specific characters in newly implanted localities. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 193 THE MAPS Heading each map-page is an outline sketch of the whole area upon which an arrow points to the islet that is enlarged beneath. The enlarged maps of the individual keys are oriented as is usual in maps and upon them is indicated, by arbitrary signs, the location and extent of the various species, each species being always represented by the same sign on the different maps. The small keys north and west of Woman Key, Mule Key, Cottrell Key, Mullet Key, East and West Crawfish Keys and Conch Key being mangrove colonies only; and Long Key and Middle Key being devoid of vegetation, are not mapped or included in detail in this paper. 194 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. TOTU6AS KEYS XARQUtJAS KEYS <^ ^ $$$>'' ^ X X i*K^******** ^ * >*&J*JI )t >t X. _, f^ n. XH^X K % tjf^Jt-^ X H X^Jt-x^ ^ 3 K^H^^x H H H K^X. H Jt X*~** x _. X. v X . . H *~ ^. XXX x' . XX, ^^SfMl Man Key. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 197 MAN KEY MARCH 13, 1904 Q) Alternanthera brasiliana (2353) 3 Galactia spiciformis (2332) Andropogon glomeratus (2325, 2357) o Hymenocallis caribaea (2326) f Avicennia nitida (2335) > Ipomoea pes-caprae (2330) fy 1 Batis maritima (2339) $ Iva imbricata (2342) < Borrichia arborescens (2360, 2334) Melanthera nivea (2333, 2348, Z Bradburya virginiana (2347, 2350) 23483) A Cakile fusiformis (2324. 2328, 2343, Y Panicum maximum (2345) 2344, 2358) "3 Paspalum distichum (2329) cf Cenchrus tribuloides (2346) ** Pithecolobium guadalupense (2362) c- Conocarpus erecta (2340) ) Rhizophora mangle (2336) Euphorbia buxifolia (2338) Sesuvium portulacastrum (2323) Cf Euphorbia havanensis (2351, 2354, ^ Solanum bahamense (2361) 2355, 2356) 5f Suriana maritima (2337) 3 Eustachys petraea (2352) * Tournefortia gnaphalodes (2341) 6 Flaveria linearis (2331, 2349) I Uniola paniculata (2359) / Waltheria americana (2327) Man Key is a narrow sand ridge about one mile long by a quarter mile wide. The southern beach rises abruptly to a bank, about four feet high in its central part, whence it slopes to the west into a narrow strand and to the east to a sea-washed spit. The brink of the plateau is occupied by a Uniola- Euphorbia association with Cakile between it and the water. Back of this association is a new aggrega- tion of Panicum and Cenchrus. The plateau itself is almost covered with Andropogon admixed with scattering plants of Waltheria, Flaveria, Ipomoea, and Melanthera, and a goodly sprinkling of Galactia and Bradburya. The extensive and marked zonal arrangement of the Uniola, Panicum, Andropogon, Borrichia, Avicennia, Batis, and Euphorbia is unique upon this key; on none other do the various elements of the flora remain in such pure colonies; nor is there found anywhere else among the keys an area so peculiarly implanted. The next feature of note, beside the remarkable zonal arrangement, is the absence of Laguncularia from the mangrove border, and Cyperus brunneus from the plateau. ip8 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. TOHTU6AS KEYS MARQUESAS KEVS i* X X XL**** X^ X x :* iO^xx^^x 4~XX***;* 2!ay&'&2& S ^K XK X^ S3Q^gKiffM>s&ss < VVyVMA < - ^ *$, Au>W X H Woman Key. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 199 WOMAN KEY MARCH 14, 1904 Andropogon glomeratus (2398) | Galactia spiciformis (2422) tf Atriplex cristata (2411) O Hymenocallis caribaea (2405) f Avicennia nitida (2410, 2429) n Laguncularia racemosa (2414, 2433)

Euphorbia trichotoma (2401, 2428) A low, sandy islet, less than a mile long and about one quarter mile wide, composed of an abrupt southeastern beach rising about three feet above the level of the sea, backed and extended by two mangrove colonies. The southeast beach is fringed with a line of Sesuvium, terminated on the west by a few plants of Cakile. On the rise above this fringe grows a nearly complete line of Uniola, back of which the open plateau of the key is clothed with a dense growth of Andropogon, amongst which are scattering plants of Panicum maximum, Hymenocallis, Euphorbia buxifolia and E. Garberi, and Waltheria. On the mud flat, between the higher land and the border of the mangroves, are sep- arated colonies of Suriana, Sesuvium, Cyperus brunneus, Atriplex cris- tata, and Lithophila vermicularis; a single individual of Dondia linearis; and two shrubs of Pithecolobium. At the western extremity of the AnJropogon community, evidently profiting by the shade cast by the Avicennias, are a few individuals of Rivina humilis laevis, Calonyction album, Solanum bahamense, and Euphorbia trichotoma. The mangrove border presents its usual association of Borrichia arborescens, Batis, Sesuvium, Laguncularia, and Avicennia, and two separated nuclei of Conocarpus erecta. The western half of the key, separated by a narrow strait, is a mangrove colony in which a new bit of dry land is in process of forma- tion. The flora of this terra nova shows mostly individual infarction in its Solanum, Suriana, Calonyction, Lithophila, Euphorbia havanensis, and Borrichia arborescens elements, while its Euphorbia buxifolia, Cen- chrus tribuloides, Cyperus brunneus, and Panicum maximum show an early tendency to communize. Its mangrove border evidences, so far, only the primal elements of the usual society Laguncularia- Avicennia. FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. r TO*TU8AS KEYS MABQUEJAi KEV5 A^' >.-***' %> CO KEY WEST Ballast Key. FEB. 1907. FLORA SAND KF.YS OF FLORIDA MILLSPAUGH. 201 BALLAST KEY MARCH 13, 1904 Ambrosia hispida (2308) Andropogon glomeratus (2320) Atriplex cristata (2315) Avicennia nitida (2306) Batis maritima (2305) Borrichia arborescens (2312) Cakile fusiformis (2317, 2318) Canavalia obtusifolia (2304) Cenchrus tribuloides (2321) Conocarpus erecta (2316) Cyperus brunneus (2319) Euphorbia buxifolia (2302) Hymenocallis caribaea (2301) Iva imbricata (2309) Monanthochloe littoralis (2307) Rhizophora mangle (2311) Salicornia ambigua (2303) Sesuvium portulacastrum (2322) Suriana maritima (2310) Tournefortia gnaphalodes (2314) Uniola paniculata (2313) This small key is separated from Man Key by a channel so nar- row that the branches of the mangroves of both nearly touch. This channel is very shallow and destined soon to be colonized by the man- grove and cause the islet to lose its identity in consolidation with Man Key. The key is now about 250x240 feet, and in the neighborhood of 2 feet at its highest point. Like Bird Key, this islet has no abrupt shore, being more or less rounded in topographic contour with the strand everywhere at a gentle slope. Its vegetation presents the odd condition of having its mangroves and Avicennias disposed at the farthest points they could possibly grow apart, instead of being, as usual, in association. This condition is repeated in the two colonies of Uniola and Euphorbia, one on the east and the other on the south strand, though there are two associated groups of these elements on the other two shores northwest and southeast. The two lines of Batis and Salicornia appear to be forming their true association with the Avicennia, and at one point Cenchrus its frequently noted camaraderie with Uniola. At the north point appears a peculiar continuous line of Ambrosia which apparently indicates that the strand at this end of the islet is in process of formation from the sea. The extensive implantation of Suriana is not pure, like the simi- lar growth on Bird Key, but scatteringly admixed with a floor growth of Cyperus and Andropogon. The small lagoon, on the eastern side, is evidently of late inclusion ; again pointing to new strand formation on this part of the key. 202 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. '"' ' TOKTU6AS KEYS MARQUESAS KEV5 ta KEY WEST nsA>n, * --*-- X X*>tx.X X X:** K _ }f Jt ^X-* X X XX. Boca Grande Key. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 203 BOCA GRANDE KEY MARCH 13, 1904 Alternanthera brasiliana (2279) Ambrosia hispida (2280) Andropogon glomeratus (2293) Avicennia nitida (2286) Batis maritima (2285) Bumelia microphylla (2291) Caesalpinia crista (2282) Cakile fusiformis (2266) Cenchrus echinatus (2300^) Cordia sebestena (2296) Cyperus brunneus (2298) Diapedium assurgens (2283) Dondia linearis (2294) Erithalis fruticosa (2269) Ernodea littoralis (2276) Euphorbia Garberi (2271) Euphorbia havanensis (2300) Flaveria linearis (2267) C D f / Gossypium religiosum (2287) Hymenocallis caribaea (2273) Laguncularia racemosa (2290) Maytenus phyllanthoides (2292) Melanthera nivea (2297) Metastelma bahamense (2277) Pectis Lessingii (2295) Phaseolus pauciflorus (2284) Pithecolobium guadalupense (2272, 2278) Rhizophora mangle (2289) Salicornia ambigua (2288) Sesuvium portulacastrum (2275) Smilax havanensis (2274) Solanum bahamense (2268) Suriana maritima (2299) Waltheria americana (2270) This most interesting of all the isolated sandy keys is about three fourths of a mile long and five eighths of a mile in width. It rises abruptly, on the west, from a narrow beach to an elevation of about 4 feet, then after exhibiting a narrow and but slightly vegetated plateau quickly slopes to two small lagoons and a mangrove-surrounded plain consisting principally of small bits of coral rock. The narrow western beach is flanked, at the base of the abrupt bank which forms the wash line, by an almost continuous line of Sesuvium, as is so often the case among these keys. The plateau association is Andropogon-Cyperus, instead of Uniola-Euphorbia,\hz latter being inexplicably absent, not even presenting a single individual of its elements. At the northern end the mangrove border association of Avicennia-Dondia-Salicornia-Batis is very characteristic, while the heterogeneous admixture of species, between this association and the beach, can but suggest a favorite resting ground for both sea and land birds. The plain of coral debris is peculiar to this key alone in the archipelago. It is nearly barren except for its odd aggregation of shrubs of Cordia, Gossypium, Bumdia, Melanthera and Maytenus, the first two of which suggest former residence of man. The passageway between the plateau and the coral plain is flanked on each side by large masses of Ambrosia that run into the Laguncularia on the north and the mangroves on the south. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 205 THE MARQUESAS GROUP The sand keys forming this group have been arbitrarily designated as "A," "B, " "C, " etc., for reference in this work, and are also so indicated upon the labels of the specimens, the maps, and in the field notes. The reason for this is that these islets are only known collectively, among the boat and turtle men, as "The Marquesas," not being individually differentiated by them. On the U. S. Coast and Geodetic- Chart No. 170, our Key "H" is noted as Round Island and the small key lying between our Key "I" and Key "A" (which was found to be covered with mangroves only) as Conch Key; these names are, however, unknown to the boat men. Mr. Lansing's observations, during his survey of the group, point to several changes having befallen the islets since the survey which resulted in the formation of the chart. Key "A" he found to be continuous'instead of composed of two portions; this was also true of Keys "G" and "H" and of Conch Key; and Key "D" has been reduced from narrowly oblong to a more or less semicircular form. These changes are in no wise peculiar but are due to the natural expansion of the mangrove colonies, erosion by the waves and current, artd the drifting or upwashing of the fine, light, coral sand of which these keys are all composed. All of these natural forces are uniting to form, in course of time, a solid island em- bracing this whole group. 206 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. TOKTU6AS KEYS OCJUE3AS KEYS 03 KEY WEST v^> Marquesas "A" FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 207 MARQUESAS "A" MARCH 10, 1904 Ambrosia hispida (2104) Andropogon glomeratus (2123) "f Avicennia nitida (2101) < Borrichia arborescens (2109) 2 Caesalpinia crista (2103) A Cakile fusiformis (2110) Calonyction album (2121) Cyperus brunneus (2122) TTt Dondia linearis (2100) Erithalis fruticosa (2119) Euphorbia buxifolia (2113) . 03 Kf T WOT FLORIDA wr-" Marquesas "B." FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 209 MARQUESAS "B" MARCH n, 1904 Andropogon glomeratus (2163) f Avicennia nitida (2165) < Borrichia arborescens (2157) . : Canavalia obtusifolia (2162) Cyperus brunneus (2159, 2161) X- v >^ :X^5^ i^*H | jx*$^iji[i v*i, v ^XKH.^V^X. ^-.-^ -^ x^ ^^^^ Sf^T-v/'Vii Wi^]^^ Marquesas FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 217 the presence of Coccothrinax jucunda and Coceolobis on this end of the islet strongly suggests that while it was occupied by charcoal burners they probably kept a swine or two; that entirely uprooted the former, and on account of them the coalers brought in and planted the latter. The southern end bears a strong vegetal resemblance to the other small islets of the group, the association showing no peculiar characters. MARQUESAS "F" MARCH 12, 1904 f Avicennia nitida (2217) < Borrichia arborescens (2220) A Cakile fusiformis (2213) : Canavalia obtusifolia (2219) c~ Conocarpus erecta (2216) 1Tt Dondia linearis (2208, 2209) Euphorbia buxifolia (2212) 9 Euphorbia trichotoma (2215) =C= Hymenocallis caribaea (2221) Melanthera nivea (2211) K Rhizophora mangle (2218) - Sesuvium portulacastrum (2223) D Solanum bahamense (2214) V Suriana maritima (2210) I Uniola paniculata (2222) This formation, only separated from "A" by a channel about 300 feet wide, shows no other character of differentiation from that key. It is about one mile in length and is mostly a mangrove colony. Its southern extremity rises in a sand ridge about 3 feet above tide, upon which is the usual Uniola-Euphorbia association. The only striking vegetal characters are the presence of Euphorbia trichotoma, the implantation of the bit of beach central to the eastern margin with Conocarpus; and the Avicennia connective between this and the next small bit of sand beach to the north. 218 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. ^FLORIDA TOTU8AS KEYS 5^> MABQUE3AS KEYS *> >;; *? 8 f n HH Marquesas " G. " FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 219 MARQUESAS "G" MARCH 12, 1904 f Avicennia nitida (2235) < Borrichia arborescens (2236) $ Cenchrus tribuloides (2229) Cyperus brunneus (2238) Euphorbia buxifolia (2225) cf Euphorbia havanensis (2232) /o, Euphorbia heterophylla (2233) 9 Euphorbia trichotoma (2224) $ Iva imbricata (2237) n Laguncularia racemosa (2227) -3 Paspalum distichum (2239) ^ Rhizophora mangle (2234) ^-> Sesuvium portulacastrum (2226) f Suriana maritima (2228) >(c Tournefortia gnaphalodes (2231) I Uniola paniculata (2230) This bit of sand and mangrove, about 200x75 ^ eet ' n extent and 2 feet above the tide, is the beginning of a connective destined to unite the group on the south. The Uniola association of the sand plateau differs in its component species from the other small keys in that the Euphorbia buxifolia element is largely supplanted by Cenchrus and Euphorbia havanensis and E. heterophylla the latter of doubtful specific differentiation. Its vegetal distinction from the other keys is also prominent in the large number of individuals of Avicennia associated in forming an unbroken landward border for the mangrove colony. 220 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. v. JL TCWTUBAS KIV3 ABC1UCJAS KEYS ,, Marquesas " H." FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 221 MARQUESAS "H," OR ROUND ISLAND MARCH 12, 1904 ^ Atriplex cristata (2246) | Avicennia nitida (2242) < Borrichia arborescens (2248) A Cakile fusiformis (2250) TU, Dondia linearis (2249) Euphorbia buxifolia (2247) n Laguncularia racemosa (2241) Melanthera nivea (2251) K Rhizophora mangle (2245) sO: Salicornia ambigua (2243) -^ Sesuvium portulacastrum (2252) G Sporobolus purpurascens (2244) f Suriana maritima (2240) This small key, about 1200 feet in area, is distinctive in having its plateau, about 3 feet in elevation, absolutely barren of vegetation, having as yet formed no Uniola association, the Euphorbia element being turned over to the Sesuvium border on the abrupt south beach. In the pasty mud at the base of the slope to the Rhizophora swamp, close to the mangroves themselves and between therti and the usual Laguncularia, is an incipient salina strip devoted solely to Salicornia bordered on the landward side by Sporobolus purpurascens. None of the other elements of the vegetal association is particularly unique. 222 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. FLORIDA TOHTU6AS KEYS MARQUESAS KEYS . 03 KiVWEST a^ax^-^t ^ ^/: -^ ^ 0ggfrMx$* ^*^6^txl? *S.X tt< f 1 ^ ^ ^ > r "T^T )+f 1 C" _ C~^ / Marquesas " I." FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 223 MARQUESAS "I" MARCH 12, 1904 f Avicennia nitida (2256) < Borrichia arborescens (2257) (^ Cenchrus tribuloides (2264) c- Conocarpus erecta (2259) Cyperus brunneus (2262) Euphorbia buxifolia (2263) tf Euphorbia havanensis (2265) ^ Eustachys petraea (2255) $ Iva imbricata (2253) X Rhizophora mangle (2258) f Suriana maritima (2261) I Uniola paniculata (2254) / Waltheria americana (2260) A small sand strip about 100 feet in length, 25 feet wide, and less than 2 feet in elevation. Its seaward shore is too abrupt for a Sfsu- vium colony, or has been recently eroded to such an extent as to have lost it. The immediate brow of the bank is given over to the usual Uniola- Euphorbia association in which the ample admixture of Suriana so near the brink proves with near certainty the erosion of this shore.. The colonization of the plateau is quite distinctive in its novel associ- ation of Eustachys and Waltheria. This association appears to have weaned the Cyperus element away from the Uniola association, which in turn has adopted Cenchrus as a substitute. The mangrove border, while retaining a complete fringe of Avicennia, here shows for the first time in the group a full substitution of Conocarpus for Laguncularia^ 224 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. TOTU6AS ICIVS MARQUESAS KEYS , FLORIDA East Key. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 225 TORTUGAS GROUP The islets of this group, the most western of the Florida Keys, are too shifting, or lacking in coral mud, to form an anchorage for Rhizophora mangle, in this respect differing radically from the man- grove-formed Marquesas group, from which they are separated by over fifty miles of open sea. Long* and Middle Keys are so low as to be awash during heavy weather and, on this account, are void of vege- tation. The details of the vegetation of the other keys of the group are as follows: EAST KEY MARCH 21, 1904 A Cakile fusiformis (2492) cf Cenchrus tribuloides (2487) Euphorbia buxifolia (2485) $ Iva imbricata (2484 and 2486) D Scaevola Plumieri (2489) Sesuvium portulacastrum (2490) % Tournefortia gnaphalodes (2491) I Uniola paniculata (2488) East Key lies about four miles north of east from Garden Key. It is little more than a mere sand bank about 280x50 feet in area. I*s west shore is narrow and rises abruptly to an elevation of about 2 feet, whence the surface slopes gradually to broad strands on the east and south. The vegetation consists principally of Cenchrus and Euphorbia with a sprinkling of Uniola at the southern end; two isolated patches of Sesuvium near the center of the islet; and the few other species scattered without definite association. 226 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. v FLOP i DA TOKTUSAS KEYS MARdUEJAS KVS . 03 KEY WEST Sand or Hospital Key FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 227 SAND, OR HOSPITAL KEY MARCH 21, 1904 Euphorbia buxifolia (2493, 2494) ? Ipomoea pes-caprae (2497) $ Iva imbricata (2496) ^ Sesuvium portulacastrum (2495) I Uniola paniculata (2498) Sand Key, the smallest vegetated key in the group, is situated about one and a half miles northeast of Garden Key. This little, oval patch of sand, known to the natives as Hospital Key, is about 50 x8o feet, and has lost nearly the same area since it was charted by the U. S. Hydrographic Survey. The central portion, which rises about three feet above the sea and comprises fully one half the surface of the islet, is occupied by a growth of Euphorbia buxifolia and Ipomoea pes-caprae flanked on the eastern border by three separated patches of Sesuvium portulacastrum, on the west by four shrubby plants of Iva imbricata, and on the north by a clump of Uniola paniculata. 228 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II.. tCM.1 >v JL TOUTUSAS KCVS ., 00 KEY WEST Garden Key. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 229 GARDEN KEY MARCH 22, 1904 b I Arharanthus viridis (2521) 4^ Argemone leiocarpa (2531) $ Atriplex cristata (2522) s Bidens leucantha (2506) Boerhaavia viscosa (2530) # Cakile fusiformis (2517, 2526) ~D Canavalia obtusifolia (2516) P Capraria saxifragaefolia (2501) T Cenchrus echinatus (2512) Cenchrus tribuloides (2511) A Cyperus brunneus (2529) B Euphorbia adenoptera (2502) U Euphorbia buxifolia (2523) G Euphorbia havanensis (2536) f Eustachys petraea (2504) K Heliotropium curassavicum (2509) >|c Hymenocallis caribaea (2514) I Ipomoea pes-caprae (2518) Iva imbricata (2520) Lithophila vermicularis (2527) Melanthera nivea (2505) Opuntia Dillenii (2537) Paspalum distichum (2528) Portulaca oleracea (2503) Sesbania sericea (2519) Sesuvium portulacastrum (2524) Sida carpinifolia (2515, 2535) Sida diffusa (2534) Sonchus oleraceus (2499, 2533) Sporobolus purpurascens (2507-8) Suriana maritima (2532) Syntherisma fimbriatum (2510) Tournefortia gnaphalodes (2513) Uniola paniculata (2525) Valerianodes jamaicensis (2500) Garden Key, the central islet of the group, is almost wholly occupied by the structure and outbuildings of Fort Jefferson, leaving to natural vegetation only a small sandy point to the northeast and a somewhat larger one to the south of the walls of the fortress. Within the bastion walls, near the officers' quarters, have been planted about thirty trees of Avicennia nitida, one Tamarindus indica, and a number of individuals of Catappa catappa, the balance of the enclosed area being devoted to a parade ground. On the western edge of this parade are a few clumps of Hymenocallis caribaea; on the parade itself a few plants of Sida carpinifolia; in the waste space back of the officers' quarters several clumps of Sida diffusa; and within the walls of a ruined powder magazine a few plants of Sonchus oleraceus. The small area of natural islet northeast of the base of the fortress walls supports an intermingling of the following species: Paspalum distichum, Cakile fusiformis, Sesuvium portulacastrum, Sporobolus pur- purascens, Uniola paniculata, Tournefortia gnaphalodes, Suriana marilima, Euphorbia buxifolia, Cenchrus echinatus, Syntherisma fimbriatum, and Iva imbricata. This vegetated area is bordered on the east by a complete line of Cenchrus tribuloides and Cyperus brunneus. The southern projection of the key presents the most interesting 230 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. flora of the Tortugas group. The great number of species on this bit of sand, not differing in itself from that of the other islets, must be due either to ballast dumping or some element connected with the presence of man. Along the west beach is a stretch of Paspalum dis- tichum with a sprinkling of Cyperus brunneus, two isolated patches of Lithophila vermicularis, and beyond these to the southern extremity a complete border of Uniola paniculata with a fringe of Cenchrus tribu- loides at its seaward base. The southern portion of the point is given up to Canavalia obtusifolia which is separated from the Uniola by a growth of Euphorbia buxifolia. In the center of the spit is a hetero- geneous intermingling of Ipomoea pes-caprae, Euphorbia btixifolia, Atri- plex cristata, Bidens leucantha, Suriana maritima, Tournefortia gnapha- lodes, Heliotropium curassavicum, Canavalia obtusifolia, Sida carpinifolia, Melanthera nivea, Sonchus oleraceus, Eustachys petraea, Capraria saxifragaefolia, Sesbania sericea, Sporobolus purpurascens, Euphorbia adenoptera and Portulaca oleracea. Near an outbuilding, a few feet from the base of the moat wall, is a clump of Opuntia Dillenii, a cluster of Amaranthus viridis, and a patch of Boerhaavia viscosa; between these and the board walk the space is occupied entirely by Canavalia obtusifolia, terminating in one plant of Sesbania sericea. The bit of sand between the walk and the east beach close to the wall of the moat is occupied by the Canavalia, Argemone leiocarpa, Sonchus oleraceus, Valerianodes jamaicensis, Iva imbricata, and immediately at the beach Ipomoea pes-caprae. On the coping of the bastions grows the only implantation of Euphorbia havanensis in the group; it is accompanied by Canavalia obtusifolia and Melanthera nivea. 232 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. > FLORIDA TORT US AS KEYS MARQUESAS KCVS . KEY wtST Bird Key. FEH. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 233 BIRD KEY MARCH 19, 1904 A Cakile fusiformis (2458, 2460, 2462, -3 Paspalum distichum (2450) 2463) P Portulaca oleracea (2459) tf Cenchrus tribuloides (2454^ ) D Scaevola Plumieri (2456) Cyperus brunneus (2452) Sesuvium portulacastrum (2461) Euphorbia buxifolia (2453, 2455) f Suriana maritima (2451) # Opuntia Dillenii (2454) jjc Tournefortia gnaphalodes (2449) I Uniola paniculata (2457) This low sand islet, situated about three quarters of a mile south of west from Garden Key, extends about 500 feet north and south, about 250 feet east and west at its broadest part, and at its highest point rises only about 3^ feet above the sea. The northern extremity is a broad sea-washed sand spit; the west beach is very narrow and rises immediately into an abrupt bank about two feet high; the east shore slopes into a broad strand, and the southern extremity forms a sand spit similar to that of the north point but less extensive. Wave action from the northwest appears to be rapidly eroding the western beach, the vegetation on the shore plainly showing the encroachment. Almost the entire Key is covered with a dense growth of Suriana maritima which extends to the verge of the west shore and to the wave limit of the east beach, clothing the center of the islet to the exclu- sion of other species. The east border is plentifully strewn with an intermingling of Cenchrus tribuloides, Cyperus brunneus, Euphorbia bux- ifolia and Tournefortia gnaphalodes, while scattering clumps of Cakile fusiformis venture out from this zone toward the sea. Two small, separate colonies of Sesuvium portulacastrum have become established at the wave line of the northern point, the space between them and the Suriana being occupied by a shrubby form of Euphorbia buxifolia (2455). Toward the southern extremity of the eastern wave limit appear two detached plants of Scaevola Plumieri and between them a small patch of Portulaca oleracea. The wave line is terminated on the south by an extensive growth of Paspalum distichum and ends with two plants of Uniola paniculata, the latter species also appearing south of a clump of Opuntia Dillenii near the hospital boat landing on the western beach. These twelve species comprise all of the vegetation observed upon the key. 234 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. ^FLORIDA TDHTUCA* KIYS MAR9UC5AS KEYS Loggerhead Key. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 235 LOGGERHEAD KEY MARCH 19, 1904 Caesalpinia crista (2479) Cakile fusiformis (2472) Calonyction album (2483) Canavalia obtusifolia (2464) Capraria biflora (2477) Cordia sebestena Euphorbia buxifolia (2475) Hymenocallis caribaea Ipomoea pes-caprae (2470) Iva imbricata (2471, 2473) Melanthera nivea (2482) ? Opuntia Dillenii (2476) P Portulaca oleracea (2480) 8 Salvia serotina (2481) D Scaevola Plumieri (2469) Sesuvium portulacastrum (2468) F Sporobolus virginicus (2474) tf Suriana maritima (2465) % Tournefortia gnaphalodes (2467) ~ Tribulus cistoides (2478) I Uniola paniculata (2466) This highest and westernmost key of the archipelago, and largest of the Tortugas group, is completely reef-invested on its eastern and western shores. It is about three quarters of a mile long by an eighth of a mile broad, with a central plateau full nine feet above tide. Although it has for years been occupied by a lighthouse and its attendants, it is nevertheless notably free of homovectent plants, Salvia, Cordia sebestena and Tribulus being the only species present that might be considered to have been brought here by man. Its central plateau, like that of Bird Key, is entirely implanted with a pure Suriana group, the individuals of which are about six feet high. The vegetation of the islet presents no associations whatever, all its species being elementally scattered subtropic, maritime "weeds. " Even the usually associated Uniola and Euphorbia appear as far separ- ated as the limits of the surface will allow. The lighthouse enclosure contains a Papaya, and several Coconut and Geiger trees, the walk being bordered by two patches of Hymeno- callis. The garden contained no flower-beds nor vegetable patches at the time of Mr. Lansing's visit. 236 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. SUMMARY This reconnaissance of a full series of isolated and grouped sub- tropic sand keys, appears to prove that such species as are able to avail themselves of avevectent and aquavectent transportation, and can withstand, or actually need, a surcharged saline soil and atmos- phere avail themselves, with more or less heterogeneity of association, of those sands upon which their seeds are cast; there to spread in just so far as their demands for nourishment and needful space will permit. Ventevectant transportation appears to play no part whatever in the vegetal colonization of such isolated portions of land. DISTRIBUTIONAL NOTES Agave decipiens : This species undoubtedly has been planted qn Marquesas "E" by the charcoal burners who once camped thereon. There are abou* a dozen of the plants together not far from the location occupied formerly by their hut.* It was probably planted there that it might serve in lieu of soap when stores of that detergent failed. Amaranthus viridis: See note under Argemone leiocarpa. Argemone leiocarpa : This species is one of the forms of the common Antillean weed A. mexicana, appearing, like its frequent companions Bidens leucantha, Sonchus oleraceus, and Amaranthus viridis, frequently about the hab- itations of man. Their introduction on Garden Key is doubtless due to ballast shifting, as are also Capraria biflora, Euphorbia adenoptera, Heliotropium curassavicum and Sesbania sericea. Avicennia nitida: Occurs only in association with the mangrove and even then only on the receding, and drying borders. (On the south side of New Providence, in the Bahamas, it is, however, found in the open but shallow sea fully a hundred yards or more from the shore.) * See under Rhitophora mangle. FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 237 Batis maritime.: See concluding paragraph under this head. Bidens leucantha: See note under Argemone leiocarpa. Borrichia arborescens: See concluding paragraph under this head. (_ 'akile fusiformis: None of the Antillean species is better adapted to dissemination by water than this, nor indeed for ready spreading when once a foot- hold is gained. See page 125. Cacsalpinia crista: Doubtless aquavectent. The pods are excellent pontoons and are often found at sea far from land. Canavalia obtusifolia: Doubtless aquavectent. The pods are excellent voyagers and the seeds retain their vitality even after prolonged salt water immersion. Capraria hi flora: See note under Argemone leiocarpa. Cenchrtis tribul aides: The fruits of this grass are especially adapted for clinging to the webbed feet of marine birds; it is, on this account, one of the first species to be implanted upon newly formed strands and islets. Coccolobis uvifera: While the Sea Grape is a common plant on the rocky keys of Florida and the shores of the Antillean Islands in general, and its appearance on these sand keys might be considered by no means extraordinary, yet I am inclined to judge that it is planted on Marque- sas "E" (the only islet of the archipelago on which it is found). Coccothrinax, jucunda : This species is common on the eastward keys of Florida and there appears no valid reason why it may not have been implanted naturally upon Marquesas "E." From the fact that this species will not survive transplantation it is certain that the supposition that it had been brought here to serve for future rethatching of the hut is erroneous. Conocarpus e recta: See concluding paragraph under this head. Cordia sebestena: The natural implantation of this species in both its localities (Boca Grande and Loggerhead Keys) is open to serious doubt. On account of the splendor of its flaming flowers it has become a common 238 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. practice in the Antilles to plant, or at least transplant, it as an orna- mental shrub. It, however, readily spreads from seed after being planted and the upper station on Loggerhead Key, among the Surianas, is quite possibly due to "seeding in." Cyperus brunneus: This species is a quite constant element of the Antillean strand flora from the Bahamian Archipelago through to Vera Cruz, Mexico. The seeds are avevectent, per pedis et intestinis. See concluding para- graph under this head. Dondia linearis: See concluding paragraph under this head. Euphorbia, adenoptera: See note under Argemone leiocarpa. Euphorbia buxi folia: This is the commonest herbaceous species of the Antillean strand flora. Its communication from island to island is accomplished prin- cipally through the medium of the feet of aquatic birds. Once estab- lished it apparently spreads, not only by the catapultic property of the fruits, but also through the drifting of the seed with the shifting sand. Gossypium religiosum: See remarks under Boca Grande- Key. Heliotropium eurassavicum: See note under Argemone leiocarpa. Hymenocallis caribaea: See remarks under Marquesas "E." Ipomoea pes-caprae and Calonyction album: I am somewhat in doubt as to whether the fruits of these plants are aquavectent (a method of transportation for which they are well fitted) or whether the seeds are avevectent; the latter, I should judge from the often high location of the species on many rocky Antillean islands, is the more probable. Iva imbricata: See concluding paragraph under this head. Jacquinia keyensis: This shrub is of very common occurrence upon the eastern keys of Florida and the islands of the Bahamian Archipelago. Notwith- standing the fact that its growth upon Marquesas "E" is unique, and represented by but two specimens, I am inclined to include it among the naturally implanted species. Laguncularia racemosa: This species is generally found on the receding border of a man- FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 239 grove colony. The exception is Key "B" of the Marquesas group, where it is present notwithstanding the fact that the mangrove is en- tirely absent; and Marquesas Keys 4< F" and "I," and Man and Ballast Keys, where although the mangrove colony borders seem espe- cially suitable to its growth, the Laguncularia has not yet, at least, become implanted. Opuntia Dillenii: This common Antillean cactus is one of the most readily avevec- tent species. Its implantation on Bird and Garden Keys is therefore not at all unnatural. Although, from its location on Loggerhead Key the introduction of the species might well be supposed to be homo- vectent, yet, as I have noted its presence on other tropic sand keys where of a certainty man would not have planted nor even conveyed it, I feel justified in considering the presence of the plant also natural in this situation. Oreodoxa regia: About half a dozen of these Royal Palms still stand on Marquesas "E" near the charcoal burner's hut* to which situation they were doubt- less transplanted from the neighborhood of Cape Sable, probably by the coalers themselves. They served the camp two purposes: that of shade, and as a much needed landfall when returning from boat expeditions. Pithecolobium guadalupense: The bony seeds of this species are partly invested by a fleshy aril attractive to birds both in color and in taste. This species becomes quite readily transplanted through the medium of the larger migrating land birds. Rhizophora mangle: This species occurs upon all the islets between Key West and the Marquesas group, and upon all the islets of that group except key "B" where the shores are too strongly current-washed to permit of its gaining a roothold. Many of the smaller keys noted upon the charts of this region proved, in so far as they could be examined, to be pure colonies of this species with no dry land among the plants. The mangrove has not yet found a resting place upon any of the Tortugas. This species yields one of the best and hardest of charcoals and was at one time extensively "burned" upon Marquesas "E". * See under Rkitophora mangle. '240 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. Salicornia ambigua: See concluding paragraph under this head. Salvia serotina: While this species is a common Antillean weed yet, from its widespread utilization as an antifebrile tea, I judge that its presence in the dooryard of the lighthouse residence on Loggerhead Key is due to intentional planting. Scaevola Plumieri: The black, pulpy fruits of this plant form a very attractive food for land birds; it thus becomes scattered far throughout the Antillean region. Sesbania sericea: See note under Argemone leiocarpa. Sesuvium portulacastruni: This is one of the commonest examples of aquavectant plants in this region. Its large, bladder-like leaves prove excellent pontoons to float the light axillary capsules. This is generally about the first herb to find anchorage upon newly formed sand islets and strands. Sida carpi nifolia: This, with its companion species, S. diffusa, is one of the com- monest grass-plat and wayside weeds of the Antilles. The introduc- tion of these two species into the lawn of Fort Jefferson on Garden Key was possibly accomplished through sowing grass seed from Key West or South Florida. Sonchus oleraceus: See note under Argemone leiocarpa. [ Thrinax keyensis: The type locality for this species is Marquesas "E, " where it is doubtless in close association with Coccothrinax jucunda. As the species have a similar appearance when neither in fruit nor flower, Mr. Lansing only collected the latter.] Tribulus terrestris: There is little doubt but that the presence of this species in the dooryard of the lighthouse on Loggerhead Key is due to intentional transplantation from Key West or Indian Key. The balance of the species in the Table of Distribution are com- mon Antillean avevectent plants that are coming into the Sand Key Flora with more or less heterogeneity, and will doubtless continue to do so and be added to by many other species of like ease of trans- portation. in FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 241 SEQUENCE OF APPEARANCE. From a somewhat wide field study of isolated insular and strand formations in the Antillean region I have come to the conclusion that the order of precedence in the clothing of the wave-formed sand keys of Florida has been substantially as follows: 1. Sesuvium portulacastrum (Aquavectent). 2. Cakile fusiformis (Aquavectent). 3. Euphorbia buxifolia (Avevectent).* ( Cenchrus tribuloides /A 4 ' | Cyperus brunneus (Avevectent).* 5. Uniola paniculata (Aquavectent). 6. Andropogon glomeratus (Avevectent).* ( Suriana maritima 7" \ Tournefortia gnaphalodes (Avevectent).* j Borrichia arborescens , . 8 " ] Iva imbricata (Avevectent).* 9. , Ambrosia hispida (Aquavectent). Of the mangrove-formed strands the order of precedence, from the mangrove nucleus toward the strand, appears to be: i. Rhizophora mangle (Aquavectent). j Avicennia nitida ,. , I Laguncularia racemosa ^ 3. Conocarpus erecta (Avevectent). ( Batis maritima 4. < Salicornia ambigua (Avevectent). ( Dondia linearis The open or sea margin of the mangrove-formed strand vegetates synchronously with the mangrove border in the usual sequence of the sand keys. An interesting comparative map, that may be consulted in illus- tration of these conclusions, is that of Woman Key, where we have not only an open or sea islet strand on the eastern part of the key, but also an isolated mangrove islet on the western part still entirely surrounded by a Rhizophora colony upon which there is an utter absence of species depending upon the sea for dissemination. * Through the medium of the feet of sea birds. 242 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. LIST OF SPECIES u > Woman Key B.illast Key Man Key Boca Grande MARQUESAS -; z ~. 1 Sand Key C.irdon Kov >. o Loggerhead | "G" -i- "i -B "C "D "t "! i i z z z z i i i I I I I I I I I I I I 1 I i I I I i i I i I i I i i i i i i i I Ambrosia hispida Andropogun glomeratus z Atriplex cristata Batis maritima i i i i i i i i i i i z z z z I z I z I z z. z z .z z z I z I 1 I z I z z z I z z I I I I i i i i z z I I 1 I I I 1 1 I I I I I i i i "z z z z z I z I I I I I I Boerhaavia viscosa Borrichia arborescens Bradburya virgin ana i i i i i i i i i i i i z z I I I I z z I I I I 1 z z I I I I I I I I I I I z I I I I I I I I I I I I I I I Bumelia micropbylla Caesalpinia crista . . Cakile fusiformis Canavalia- obtusifo a Capraria birlora Cenchrus echinatus Coccolobis uvifera Coccothrinax jucunda Conocarpus erecta Cordia sebestena Cyperus brunneus Diapedi um assurgens Distichlis maritima Dondia linearis Erithalis fruticosa Ernodea littoral is Euphorbia adenoptera Garberi I I I I I i I I I I i bavanensis heterophylla trichotonia Eustachys petraea Flaveria linearis . . . . Galactia spiciformis Gossypium religiosum Heliotropium curassavicum Hymenocallis caribaea Ipomoea pes-capras Jacquinia keyensis I 1 i i i i i i i i i i i i i i Lan tana i nvoluc rata I I I I I I I i I i i i z 1 I I z- z z z I z' I z I I I Litbophila vermicularis . Maytenus phyllantboides Melanthera nivea Metastelma bahamense Monanthochloe littoral is Opuntia Dillenii Oreodoxa regia Panicum maximum Paspalum distichuni PassiHora minima Pectis Lessingii Pharbitis cathartica Phaseolus paucirlorus . . . . Pithecolobium guadalupense... Portulaca oleracea Rivina humilis laevis z I z I I Salicornia ambigua Salvia serotina Scaevola Plumieri Sesbania sericea FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 243 LIST OF SPECIES u It Woman Key f u = Boca Grande MARQUESAS East Key Sand Key "i a . a a Bird Key Loggerhead | a *"* C D T r "G 1 'T 1 I I I I 1 I I I X I I I i i i i i i i i i i i I 1 I I i i i i i i i I I X. I X i i X X i X X virginicus Syntherisma fimbriatum . . . X X I I I I I X I Tournefortia gnaphalodes Valerianodes jamaicensis ... . . INDEX. Ballast Key 201. Bird Key 233. Boca Grande Key 203. Conch Key 193, 205. Cottrell Key 193. Crawfish Keys 193. East Key 22;. Fort Jefferson 229. Garden Key 229. Hospital Key 227. KeyC 195. Loggerhead Key 235, Long Key 193, 225. Man Key 197. Marquesas Group 20;. "A" 207. "B" 209. "C" 211. "D" 213. "E" 215 "F" 217. Marquesas "G" 219. "H" 221. " I " 223. Middle Key 193, 22; Mule Key 193. Mullet Key 193. Round Island 205, 221. Sand Key 227. Tortugas Group 22$. Woman Key 199. 245 UNIVERSITY OF ILLINOIS-URBANA