PENTANDRIA. DIGYNIA. 201 



white and furfuraceous scales. Male flowers naked, 

 terminal. Calix inflated, whitish, and membranaceous, 

 somewhat g'lobose-campanulate, entire to the orifice; ex- 

 ternal dentures greenish, small and obtuse; internal 

 longer and acute, at first incumbent upon the stamens, 

 afterwards nearly erect, deltoid and acute. Stamina 5, 

 exserted, partly combined at the base, filaments capil- 

 lary; anthers at first fulvous, at length, after dehis- 

 cence, bifid at either extremity. Hab. In sterile and 

 saline places, near the IMissouri; abundant near Fort 

 Mandan, &.c. Flowering in May. I have never seen 

 any but male plants, and am unacquainted with the seed. 

 It resembles a small Atriplex or Chenopodiumy in its leaves, 

 and terminal conglomerated flowers. 



To this genus have been referred by its founder some 

 of the species of Salsola. 



287. ULMUS. L. (Elm.) 



Calix campanulate, 4 or5-cIeft. CoroUa none. 

 Samara \ compressed, encompassed by a mem- 

 branaceous alated border. (^Stamina sometimes 

 4 and also 8.) 



Tree.q or rarely shrubs; leaves retrorsely asperate, often 

 oblique at tlie base; flowers fasciculate, conglomerate, 

 appearing before the leaves. 



Species. 1. U. americana. 2. nemoralis. 3. fulva. 

 (Slippery Elm.) 4. alata. Leaves much smaller than 

 those of any other American species. Hab. In Tennessee 

 on the banks of the French Broad river, and in Carolina 

 and "Virginia. 



Of this genus there are 3 species, in Europe, 1 in Sibe- 

 ria, 1 in China, and a species of doubtful genus in India» 



288. PLANERA. Gmelin. 



Polygamous. — Calix membranaceous, sub- 

 campanulate, 4 or 5-cIeft. Corolla none. Stig- 

 Tiias Si, oblong, glandulous, divergently recurv- 

 ed. Capsule (nut?) subglobose, membranace- 

 ous, 1 -celled, not opening, smooth or aquamu- 

 lose (not winged) 1-seeded. 



Masculine flowers intermixed with the others; stamina 

 4 to 6- Leaves and flowers resembling those of Ulmus, 

 to which genus it is very nearly allied. Michaux. 



t The Elm aftbrds a genuine example of this species of fruit. 



