200 €L. AROIDE.E (brown). \Raphidophora . 



2. R. africana, N. E. Br. in Kew Bulletin, 1897, 286. Stem 

 moderately stout, about J-J in. thick, rooting at the nodes, climbing to 

 a height of 80-100 ft. Leaves glabrous; petiole G-12 in. long, sheath- 

 ing for the greater part of its length, thickened at the apex ; blade 

 8-21 in. long, 2J-4| in. broad, obliquely elongate-oblong-lanceolate, 

 acuminate, cuneate at the base ; lateral veins numerous, parallel, 

 ascending, slightly curved. Peduncles 8-5 in. long, 2 lin. thick, arising 

 near the apex of the branches, in the axils of membranous lanceolate 

 acute bracts, glabrous. Spathe 3J-4|- in. long, in the convolute stage 

 cylindric, |-1 in. in diam., produced into a stout beak about an inch 

 long, not seen expanded, very deciduous, white. Spadix sessile 2 J-3J in. 

 long, 1 in. thick, cylindric, obtuse. Ovary imperfectly 2 -celled ; style 

 very short and inconspicuous ; stigma subquadrate, or elongated parallel 

 to the axis of the spadix. Ovules several, ascending from near the 

 base of the placentas. 



Upper Guinea. Sierra Leone : near Kurusu, Scott-Elliot, 5524 ! on humus 

 of wood by a stream near Sakuru, Scott-Elliot, 4940 ! Ashanti : Assin-Yan- 

 Coomassie, Cummins, 47 ! Fernando Po, Mann, 103 ! 



Okder CLI. LEMNACE-ffi. (By N. E. Brown.) 



Flowers seated in a cavity at the margin or in the upper surface of 

 the frond, consisting of 1-2 stamens accompanied by a sessile ovary, 

 either naked or enclosed in a membranous spathe (or perianth ?), which 

 ruptures irregularly as the stamens mature. Stamens exserted from 

 the frond ; filaments filiform ; anthers 1-2-celled ; cells subglobose, 

 opening by transverse lateral or terminal slits. Ovary narrowed into 

 a style or with a subsessile stigma, 1-celled; placenta basal; ovule 

 solitary or several in an ovary, anatropous, semi-anatropous, or ortho- 

 tropous. Fruit 1- to several- seeded, indehiscent or opening trans- 

 versely. Seeds minute, albuminous ; embryo straight, axile. — Small or 

 minute, gregarious, floating plants, consisting of suborbicular, elliptic, 

 obovate, oblong or linear fronds of cellular tissue, with or without 

 rudimentary vessels, usually 2 or more fronds connected together as 

 one plant, flat on both sides or more or less convex beneath, sometimes 

 as thick as broad, developing young fronds (which remain attached to 

 the parent frond for some time) from a cavity (bud-cavity) or cavities 

 placed near or at the basal end of the frond, rootless, or producing one 

 or more roots from the middle of the undersurface. 



Genera 2. Species about 28. Found in all warm and temperate countries, 

 floating on still water. For complete acrounts of this Order see Hegelmaier, Die 

 Lemnaceen, and in Engler Jahrb. xxi. 268. 



Frond with 1 or more roots. Flowers seated in a 



cavity at the margin of the frond . . .1. Lemna. 



Frond rootless. Flowers soated in a cavity in the 



upper surface of the Irond . . . ,2. Wolffia. 



