D E S 



DESERT Island, Mount. Add— Mount Defert con- 

 tains 1047 inhabitants. See Eden. 



DESMANTHUS, in Bolmy, fo called by the late pro- 

 fetTor Willdenow, who firft feparated the genus we are 

 about to defcribe from Mimosa ; fee that article, and 

 Acacia of the prefent volume. This name feems to be 

 compofed of J<^u«, a !,m,M^, and «v9oc, afoiver; alludmg 

 perhaps to the ftrap-like filaments of the neutral flowers, 

 common to every fpecies.-Willd. Sp. PI. v. 4. 1044. Ait. 

 Hort. Kew. v. 5. 4J7. — Clafs and order, Polygnmm Mo- 

 noecin ; or rather perhaps Decantiria Momgynia. Nat. Ord. 

 Lomentacea, Linn. Legumtnof-t-, JulT. 



Gen. Ch. Cal. Perianth inferior, of one leaf, tubular, 

 with five teeth. Cor. of one petal, funnel-lhaped, regular, 

 more or lefs deeply five-cleft, fometimes of five petals. 

 Stam. Filaments ten, rarely but five, capillary, equal, very 

 long ; anthers incumbent, oblong. Pijl. Germen fuperior, 

 ovate-oblopT ; ftyle thread-fhaped, the length of the ila- 

 mens ; ftigma dilated, abrupt. Perk. Legume oblong, 

 comprefTed, of two flat valves, and one cell, feparated into 

 feveral by tranfverfe oppofite ftriftures in the valves. Seeds 

 numerous, oblong, ftalked. Several flowers, below the 

 perfeft ones, are neuter, having dilated lanceolate Jlamens, 

 without anthers, no efficient pift'il, and fometimes no corolla. 



EfT. Ch. Calyx five-toothed. Corolla deeply five-cleft. 

 Stamens definite. Piftil one. Legume of two valves. 

 Some flowers neuter, with dilated, flat, abortive ftamens. 



Obf. Although the definition of this genus is not fo 

 ftriking as could be wiflied, it feems to us tolerably natural, 

 being diftinguifhed from Acacia by the definite number of 

 its Jlamens, always twice as many as the divifions of the 

 corolla, and by the prefence of feveral neuter flowers, in 

 the lower part of each tuft, or fpike, known by their 

 dilated, ftrap-fhaped Jilaments, deftitute of anthers, and 

 more or lefs different in colour from the perfeft flowers. 

 We are neverthelefs aware, that generic charafters founded 

 on fuch anomalies or imperfeftions, are always the leafl 

 folid ; thefe neutral flowers, apparently created for no end, 

 being doubtlefs liable to become, according to circum- 

 ftances, perfeft in one organ of impregnation or the other. 

 The habit of the genus before us is pretty uniform, having 

 doubly pinnate leaves, with numerous, oblong, obtufe, 

 crowded leafets ; axillary, folitary, ftalked, oblong /pikes, 

 of crowded taflel-Hke _y?on;erj- ; and flat, generally broad, 

 elliptic-oblong, fmooth legumes, whofe tranfverfe ftriftures 

 make them refemble the jointed fruit of what now remains 

 as Mimofa, but their valves do not fplit at thofe ftriftures. 

 As only ten fpecies of Defmanthus are defcribed, we fliall 

 give the whole. They are all of tropical origin ; partly 

 herbaceous, and fometimes annual, with fenfitive leaves ; 

 partly flirubby. 



Seft. I . IVithout thorns. 



1. D. lacujlris. Lake Defmanthus. Willd. n. i. (" Mi- 

 mofa lacuftris; Humb. and Bonpl. PI. cequinod. t. 16.") 

 — ^ Thorns none. Firft divifion of the leaves of three 

 pair ; fecond of many pair. Spikes ovate. Stalks brac- 

 teated. Stem round, creeping." — Native of marflies in 

 South America. Root perennial. Stem herbaceous. Firft 

 divifions of the leaves an inch and a half long. Leafets 

 numerous, linear, obtufe at each end. Spikes barren in 

 their lower part, each fupported by a ftalk longer than the 

 iohagc, furniflied with two or three ovato-lanceolate deci- 

 duous iraSw. Legume oblong, pointed, with from four to 

 i\^ feeds. Very nearly related to the following. Willdenow. 



2. D.natans. Floating Defmanthus ; or Aquatic Sen- 

 f.tive. W.lld. n. 2. Ait. n. i. Andr. Repof. t. 629. 

 (Mimofa natans; Valil Symb. v. 3. 102. Roxb. Coro- 



D E S 



mand. v. 2. 1 1, t. 119. M. orientalis non fpinofa, rariori-i 

 bus ramis, floribus fpicatis ; Pluk. Almag. 252. Phyt. 

 t. ;^07. f. 4. Neptunia oleracea ; Loureir. Cochinch. 654. 

 " Niti-todda-vaddi ; Rheede Hort. Malab. v. 9. 35. t. 20.") 

 — Thorns none. Firft divifion of the leaves of three pair ; 

 fecond of many fmooth-edged leaflets. Spikes oblong, in- 

 terrupted. Stalks moftly without brafteas. Stem round, 

 floating, with tufted roots from the lower joints. — Native 

 of fredi-water lakes, pools, and flow ftreams, in the Eaft 

 Indies, Cochinchina, S:c. Loureiro fays it is cultivated in 

 the laft -mentioned country, as an ingredient in falads, being 

 tender and agreeably fweetifli, though not very falutary to 

 the ftomach. The plants are tied to ftakes, to prevent 

 their being carried away with the ftream. The root is 

 annual, entirely floating, as well as the round, fmooth, 

 branched, leafy ftems, whofe lower joints fend forth tufts of 

 compound radicles, their interftices being often fwollen, or 

 fpongy, at one fide, as if to render the herb more buoyant. 

 Leaves alternate, ftalked, doubly pinnate, fmooth, bright 

 green ; fecondary divifions from one to two inches long, 

 each of twelve or thirteen pair of elliptical, entire leaflets, 

 which fold together flowly when touched ; their edges 

 fmooth. Stipulas membranous, half-ovate, or heart-fhapcd, 

 obtufe. Common Jlotverflalis generally naked ; fometimes 

 furnifhed with a bradea or two. Spike oblong, more or lefs 

 crowded. Corolla greenifh. Ahortive filaments of the lower 

 floivers large, lanceolate, yellow, very confpicuous. Z/f- 

 gumes five or fix from each fpike, an inch in length, purplifh- 

 brown, fmooth, elliptic-oblong, pointed. Seeds oval, from 

 four to eight, forming a central row, inferted by a flender 

 thread alternately to each margin of the legume. Koenig 

 fent fpecimens of the following to Linnceus, but not, as far 

 as we can difcover, of the prefent fpecies ; while the in- 

 formation he communicated regarded both fpecies, which 

 pofiibly he might originally confound, thinking the irique- 

 trus a variety caufed by growing out of the water. How- 

 ever this might be, his natans is certainly the prefent plant, 

 to which alone that name can apply. 



3. D. triquetrus. Triangular-llalked Defmanthus. Willd. 

 n. 3. (Mimofa triquetra ; Vahl Symb. v. 3. 102. M. 

 natans; Linn. Suppl. 439.) — Thorns none. Firft divifion 

 of the leaves of two or three pair ; fecond of many rough- 

 edged leaflets. Stipulas pointed. Spikes globofe. Stalks 

 brafteated. Stems proftrate ; triangular in their upper 

 part. — Native of the dry borders of fields at Tranquebar. 

 Kcenig in the Linnaean herbarium. Root woody, perennial. 

 Stems feveral, from a fpan to a foot or more in length, her- 

 baceous, prollrate, rather zigzag, leafy, fmooth, fomewhat 

 glaucous, fcarcely branched ; nearly round at the bottom, 

 but triangular above. Leaves about half the lize of the 

 former, on much Ihorter ftalks, and eiTentially diftinguilhed, 

 if we miftake not, by the roughnefs of their edges, caufed 

 by fmall clofe-prefTed brilHes. The flipulas are obliquely 

 ovate, ribbed, with a tapering briftly point, which we do 

 not find in D. natans. Floiverflalks not much longer than 

 the leaves, each bearing one or more broad clalping braQeat, 

 Spikes Ihort and roundifh. Legumes elliptic-oblong, obtufe, 

 with four, five, or fix feeds. 



4. D. plenus. Semi-double Yellow Defmanthus. Willd. 

 n. 4. Alt. n. 2. (Mimofa plena; Linn. Sp. PI. 1502. M. 

 foliis duplicato-pinnatis, fpicarum floribus inferioribus plenis, 

 caule inermi procumbente ; Linn. Hort. Upf. 145. n. 3. 

 M. non fpinofa, paluftris et herbacea, procumbens, flore 

 luteo pleno ; Rel. Houft. 10. t. 23. M. n. 2 ; Mill. Ic. 

 V. 2. 122. t. 182. f. 2.) — Thorns none. Firft divilion of 

 the leaves of three or four pair ; fecond of numerous oblong 

 fmooth-edged leaflets. Spikes ovate. Stalks brafteated. 



Stem 



