cxLi. roNTEDERiACE.E (brown). [IIete7'anth€ra. 



1. HETERANTHERA, Ruiz et Pav. ; Benth et Hook. f. Gen. 

 PI. iii. 888. 



Perianth with a distinct tube ; segments equal, spreading, oblong. 

 Stamens 3 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 

 3 -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. PI, Welw. ii. 67 as Heteranthera sp., does not belong to the order 

 PoNTEDERiACE^, but to Alismace.5;, 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 . . . . . . . 1. H. callcBfolia. 



Perianth-tube 2^-3 lin. long ; closed flower with 



1 stamen . , . . . . . 2. H. kotschyana. 



Spike with more than one closed flower, some being 



mingled with the expanded flowers . . . , Z. S. Potamogeton. 



1. H. callsefoliay Reichh. ex Kunth, Enum. iv. 121 (hy errw 123). 

 Plant about a foot high, herbaceous, glabrous. Stem creeping and 

 rooting in the mud in the lower part. Leaves 2-3 in. long, lJ-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 2 J 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. long, 

 of the other flowers 4-5 hn. long, oblong, trigonous. — Solms in DC. 



