206 CLI, LEMNACEZ (BROWN), | Wolffia. 
Jahrb. xxi. 302; Rendle in Cat. Afr. Pl. Welw. ii. 92. Zelmatophace 
cylindracea, Welw. ex Hegelmaier, Monogr. Lemn. 123. 
Lower Guinea. Angola: Libongo; in rocky pools on the mountains behind 
the Banza de Libongo, in the purest, freshest drinking-water, where no other plant 
grows, Welwitsch, 212. 
Orper CLIT. ALISMACEAS, (By C. H. Wright.) 
Flowers regular, hermaphrodite, moneecious or polygamous, very 
rarely diecious. Perianth-segments 6, 2-seriate or very rarely 1-seriate 
‘by the absence of the inner whorl, imbricate ; outer usually herbaceous, 
concave, nerved, persistent ; inner usually larger, petaloid, deciduous. 
Stamens 6 or more, rarely 3, hypogynous or inserted on the base of the 
perianth-segments ; filaments terete or flattened ; anthers basifixed, or 
dorsifixed near the base, erect, obtuse, shortly bifid or with prolonged 
connective, dehiscing by lateral or more or less dorsal longitudinal slits. 
Carpels 6 to many, rarely 3, arranged in a verticil or spiral, distinct or 
connate at the base, sessile or shortly stalked, 1-celled; receptacle flat, 
oblong or globose; style subterminal or ventral, rarely absent ; stigma 
terminal and small or slightly capitate, or ventral (rarely dorsal) and 
decurrent ; ovules solitary or 2 superposed, attached to the inner angle 
of the carpel, or numerous on reticulate parietal placentas. Fruit- 
carpels distinct or connate at the base, 1-celled, crustaceous, coriaceous 
or membranous, usually bearing the remains of the style, indehiscent 
or dehiscing by the ventral suture, very rarely circumscissile at the 
base. Seeds small or minute, ovoid, oblong or compressed ; testa mem- 
branous or coriaceous, smooth, rugose or slightly spiny ; albumen none; 
embryo horseshoe-shaped ; radicle thickened.— Aquatic or marsh herbs, 
erect, rarely floating, usually glabrous, with milky juice, scapigerous or 
caulescent, perennial, rarely annual. Rhizome short or long. Leaves 
erect, rarely floating, radical or clustered at the nodes of a creeping 
stem, petiolate; lamina various, often pellucid-dotted or -striped ; 
nerves converging towards the apex of the lamina. Inflorescence 
indefinite, of racemose or spicate verticils, more rarely pseudo-umbellate 
or with solitary flowers; bracts at the base of the verticils or umbels, 
membranous ; bracteoles small. Flowers white or rose, rarely yellow 
or blue. 
Genera about 13, species abont 60, in fresh water throughout the globe except in 
the frigid zones. 
TRIBE I. Alismeve.—Ovule solitary and basal, or 2 (rarely more) attached 
£o the inner angle of the carpel. Carpels indehiscent. 
*Tnner perianth-segments petaloid, larger than the outer. 
Carpels on a small receptacle. 
Flowers hermaphrodite —. Z : : .. 1. ALISMA. 
Flowers polygamous . : : : ; 2. LIMNOPHYTON. 
Carpels on a large oblong or globose receptacle. 
Flowers monecious 3. LopHOTOCARPUS. 
Flowers hermaphrodite 4. EcHINODORUS. 
Flowers dicecious = ° 5. RAvUTANENIA. 
