POGOGYNE 525 



Podorungia Baill. Acanthaceae (iv. B). i Madag. 



Podosciadium A. Gray (Eulophus p.p. EP.}. Umbelliferae (in. 5). 



2 Calif. 



Podosemum Desv. = Muehlenbergia Schreb. p.p. (Gram.). 

 Podosperma Labill. = Podotheca Cass. (Comp.). 

 Podospermum DC. = Scorzonera L. p.p. (Comp.). 

 Podostelma K. Schum. A>-clepiadaceae (n. i). i Abyssinia. 

 Podostemma Greene (Asclepias p.p.). Asclepiad. (n. i). 6 N. Am. 

 Podostemaceae (EP. and BH. inch Tristichaceae). Dicotyledons 

 (Archichl. Rosales ; Multiovulatae aquaticae BH. ). 22 gen., 100 sp. 

 trop. A remarkable fam. of plants living only in rushing water, and 

 growing only on rocks in rivers. The morphology of the veg. organs 

 is extremely varied and complex. The seeds are shed on the rocks 

 during the drier season of the year, and germinate when the rains 

 cause them to be submerged. The primary axis is usu. small, and 

 from the base there buds out a green thallus, usu. of adv. root nature. 

 In Podostemon, &c. it is filamentous, creeping on the rock, and 

 attached to it by hairs or exogenous projections termed haptera. In 

 Dicraea it is freely swimming and often ribbon-like or sea-weed-like. 

 In Hydrobryum it is flattened, creeping, lichen-like. Other compli- 

 cations occur in Castelnavia and others. From the thallus in most 

 cases endogenous secondary .shoots arise, and remain veg. (1. alt., 

 simple or much divided) till the latter part of the rainy season, when 

 they form fls. which open when exposed by the fall of the water. The 

 plants die after shedding their seed, unless an early rise of water 

 occurs. Their outer tissues are usually very siliceous. Fls. simple, 

 5 , reg. or not, naked, enclosed in a spathe, hypog. A i-2-oc , G usu. 

 (2) 2-loc. with thick axile plac. Ovules oo (exc. Farmeria), anatr. 

 Caps.; exalbum. seeds. The more dorsiventral the veg. organs, the 

 more dorsiventral in general is the fl., the phenomenon showing pro- 

 gressively in A, G, fr. , seed, and embryo. Chief genera : Rhyncholacis, 

 Mourera, Podostemon, Dicraea, Hydrobryum, Castelnavia. [For full 

 details see Willis in Ann. Pcrad. i, 1902 and literature there quoted.] 



Podostemon Tul. Podostemaceae. 12 trop. and subtrop. 



Podostigma Ell. Asclepiadaceae (n. i). i S.E. U.S. 



Podotheca Cass. Compositae (4). 5 temp. Austr. 



Podranea Sprague (Tecoma p.p.). Bignoniaceae (2). 2 warm Afr. 



Poecilandra Tul. Ochnaceae. i Guiana, N. Brazil. 



Poecilanthe Benth. Leguminosae (in. 6). 3 Brazil. 



Poecilochroma Miers. Solanaceae (2). 8 Peru, Ecuador. 



Poeciloneuron Bedd. Guttiferae (iv). 2 S. India. 



Poecilopteris Presl Leptochilus Kaulf. 



Poecilostachys Hack. Gramineae (10). i Madag. 



Poederiopsis Rusby (Pacderia p.p.). Rubiaceae (il. 6). I Boliv. 



Poeppigia C. Presl. Leguminosae (n. 8). i trop. Am., VV.I. 



Poga Pierre. Rhizophoraceae. i Gaboon. 



Poggea Guerke. Flacourtiaceae (2). 2 W. trop. Afr. 



Poggeophyton Pax. Euphorbiaceae (A. n. 2). i W. trop. Afr. 



Pogochloa Sp. Moore. Gramineae (10). i Matto Grosso. 



Pogocybe Pierre. Leguminosae (li. 7). i Cochinchina. 



Pogogyne Benth. Labiatae (vi). 3 California. 



