2 CXLI, PONTEDERIACEE (BROWN). | Heteranthera. 
1, HETERANTHERA, Ruiz et Pav. ; Benth et Hook. f. Gen. 
Pl, iii. 838. 
Perianth with a distinct tube; segments equal, spreading, oblong. 
Stamens 8 or in the closed flowers of some species 1, affixed to the throat _ 
of the perianth-tube, exserted, more or less unequal ; filaments filiform ; 
anthers oblong. Ovary 1-celled with 3 parietal placentas, or imperfectly 
8-celled with very prominent placentas; style filiform; stigma thick- 
ened; ovules numerous, biseriate. Capsule oblong or linear; pericarp 
thin. Seeds numerous, ovoid, ribbed.—Aquatic herbs, with the lower 
part of the stem creeping and rooting in the mud. Leaves with long 
petioles sheathing at the base, and cordate, ovate, or reniform blades, 
or all linear and submersed. Flowering shoots bearing one leaf, whose 
sheath embraces the membranous spathe, which subtends the terminal 
flower-spike or includes 1-3 flowers. Flowers spicate, small, blue, 
whitish or yellow, all-alike and expanding, or one or more cleistogamous 
and enclosed in the sheath of the leaf at the base of the spike. 
A genus of about 9 species, 3 in Africa, the rest in Tropical and North America. 
The plant collected in Angola by Welwitsch (3015), and enumerated by Rendle 
in Cat. Afr. Pl, Welw. ii. 67 as Heteranthera sp., does not belong to the order 
PONTEDERIACE#, but to ALISMACER, and may be a species of Alisma or Sagittaria. 
There are no perfect flowers upon the specimens ; the buds which I have dissected 
consisting of a series of imbricating, complicate, boat-shaped segments, arranged 
distichously, 
Spike with one closed flower, concealed in the spathe at 
its base. 
Perianth-tube 3-5 lin. long; closed flower with 
3 stamens é a ‘ ° ° . - lL. H. callefolia. 
Perianth-tube 23-3 lin. long ; closed flower with 
1 stamen ° : “ - ° . . 2. H. kotsehyana, 
Spike with more than one closed flower, some being ~ 
mingled with the expanded flowers . “ : . 3. H. Potamogeton. 
1, H. calleefolia, Reichb. ex Kunth, Enum. iv. 121 (by error 128). 
Plant about a foot high, herbaceous, glabrous. Stem creeping and 
rooting in the mud in the lower part. Leaves 2-3 in. long, 14-2 in. 
broad, ovate, subobtuse, or shortly and obtusely pointed, cordate at the 
base, with petioles 4-8 in. long, erect or ascending. Flowering stems 
about 2 in.long. Flower-spike about 4 in. long, with a submembranous 
spathe at its base. Flowers several, sessile, ebracteate, whitish; the 
basal flower concealed in the spathe within the sheath of the leaf, never 
expanding, having 3 stamens like the others. Perianth-tube of the 
expanded flowers 3-5 lin. long, cylindric; lobes about 24 lin. long, 
oblong, obtuse, spreading. Stamens 3, shortly exserted. Ovary oblong, 
trigonous, narrowed into a filiform style as long as the stamens; stigma 
slightly thickened. Capsule of the basal closed flower 6—9 lin. Jong, 
of the other flowers 4—5 lin. long, oblong, trigonous.—Solms in DC. 
