OF INDIA AND CEYLON. 
229 
bracts. (This diagnosis requires slight modification if the 
American species be included.) 
Flowers zygomorphic, naked, terminal, with tubular or funnel- 
shaped erect spathe which ruptures irregularly at the tip. Stameus 2 
or 1, monadelphous, with staminode at each side of common axis and 
sometimes at the fork of the partial filaments. Pollen didymous 
Ovary ellipsoidal ; stigmas 2, simple, subulate, with small papillæ. 
Capsule unequally lobed, 8-ribbed ; one valve persistent, with 3 
decurrent ribs, the other deciduous. 
Primary axis, in the only known case, small and little developed, 
non-floriferous. Thallus phylogenetically of root nature, narrow cylin- 
drical or flattened, rarely over 3 mm. wide, creeping over the rocks, 
attached by hairs and haptera, exogenously branched (always ?). 
Secondary axes oo, endogenous from sides and axils of thallus, erect or 
more or less prostrate, many-flowered, with usually distichous com- 
pound (American) or simple leaves, branched from the lower axils of 
dithecous leaves. 
Herbs of eddies and rapids, in mountain streams. Many 
species, chiefly S. American ; one in Mexico and S.E. United 
States ; two in India and Ceylon. 
The position of this genus and its relation to others has 
been discussed above in general terms. I have excluded 
from it the Tulasnean genera Hydrobryum, Dicræa, and 
Mniopsis, which I think were merged with it by Weddell 
and Bentham on insufficient evidence. But all these genera 
must to some extent be regarded as artificial until we have 
a more detailed knowledge of the various species included in 
them. 
Stamens usually 2. Flower not 
cleistogamic. Ovary not winged P. subulatus,Gardn. 
Stamen 1. Flower cleistogamic. 
Ovary with 6 broad wings ... P. Barberi, Willis. 
PODOSTEMON SÜBÜLATUS, Gardn. in Calc. J. N. H., 
VII., 1846, p. 184 ; Tul., Wedd., Wight, Hooker, Warming, 
&c., 11. cc.; P. dendroides, Thw. MS. 
Stamens usually 2. Ovar\ not winged. Thallus thread- 
like. 
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