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WILLIS : PODOSTBMACEÆ 
Siamese species P. Schmidtianum, Wmg., cannot be settled 
till we know its fruit : P. acuminatum, Wmg., is a Hydro- 
bryum (lichenoides, Kurz), and P. Wallichii, Wmg., is a 
Dicræa. 
We thus get the following as a preliminary grouping of 
the Eupodostemeæ : — 
Asiatic Species. 
Dicræa, Du Pet. Th. elongata, dichotoma, minor, Wallichii, 
stylosa. 
Ceratolacis, Wedd. 
Podostemon, Michx. subulatus, Barberi, (?) Schmidtianum. 
Mniopsis, Mart, et Zucc. 
Oserya, Tul. et Wedd. 
Castelnavia, Tul. et Wedd. 
Griffithella, Warming. Hookeriana. 
Willisia, Warming. selaginoides. 
Sphærothylax, Biscliojf. 
Leiothylax, Warming. 
Cladopus, Hj. Moll. Nymani. 
Hydrobryum, Endl. Griffithii, sessile, olivaceum, Johnsonii, 
lichenoides. 
Farmeria, Willis. metzgerioides, indica. 
The Generic and Specific Limits of the Asiatic 
Forms. 
In an order of plants of such unusual features, such 
variability, and such polymorphism, it is of course impos- 
sible to draw the specific limits with any accuracy or certainty 
until the life-histories and the morphology of the various 
forms have been studied in detail. There is little doubt in 
my mind that the number of distinct forms will ultimately 
prove to be very great, and that there will be much dispute 
over their claims to specific rank, as with many other 
variable forms. Weddell* and Goebelf have already 
called attention to the fact that in the large rivers of 
South America the forms are different at each successive 
* Sur les Podosfcemacées en général et leur distribution géographique en 
particulier. Bull. Soc. Bot. France, XIX., 1872, p. 50. 
f Pflanzenbiologische Schilderungen, II., p. 333. 
