CCXXI. PODOSTEMACE.E. 7:j? 



CCXXI. PODOSTEMACE^E. 1 



(PODOSTEME^E, Richard. PODOSTEMAGEJE, Lindl.} 



[FLOWERS $ or diclinous. PERIANTH or simple. ANDRCECIUM hypogynous, 

 I-3-seriate. STAMENS definite or indefinite. OVARY l-3-celled- t STIGMAS 1-8, sessile 

 or on a style ; OVULES numerous in the cells. CAPSULE septicidal. SEEDS minute, 

 albuminous. Aquatic HERBS, sometimes frondose, often resembling Algae or Hepaticese. 



WATER-PLANTS, with a distinct simple or branched stem and leaves, or with 

 these confluent into broad or narrow Alga-like fronds. INFLORESCENCE various, 

 often scapose ; scapes 1- or many-flowered, arising from a tubular sheath or involucre, 

 or naked. FLOWERS unisexual or $ , naked or monochlamydeous, usually enclosed 

 in a spathaceous marcescent involucre, which is at first closed, then bursts ; mouth 

 2- or more- lobed. PERIANTH 0, or calycine or petaloid, 3-lobed or -partite, mem- 

 branous, marcescent. STAMENS definite or indefinite, free or inonadelphous, erect ; 

 filaments linear flat or membranous, marcescent; anthers ovate-oblong or linear, 

 2-lobed, dorsifixed, dehiscence longitudinal; pollen powdery, globose didymous or 

 3-gouous. STAMINODES filiform or subulate, as many as and alternate with the stamens, 

 or inserted with them or outside them, or more than them, or 0. OVARY free, sessile 

 or stipitate, central or excentric, smooth or costate, 1 3-celled ; style cylindric or ; 

 stigmas 2-3, simple or dilated or laciniate or toothed, rarely 1 capitate ; ovules 

 numerous in each cell, attached to thick axile or slender parietal placentas, ana- 

 tropous. CAPSULE 1-3-celled, septicidally and septifragally 2-3-valved, many- 

 seeded ; valves equal and persistent, or unequal, the smaller deciduous. SEEDS 

 microscopic, compressed ; testa mucilaginous ; tegmen membranous ; albumen 0. 

 EMBRYO straight, oily ; cotyledons erect ; radicle very short, obtuse. 



TEIBE I. HYDROSTACHYEJE. Flowers naked, dioecious. Ovary 1-celled ; carpels 2, alter- 

 nating with bracts ; placentas linear, parietal. Hydrostachys. 



TRIBE II. EUPODOSTEMACE^:. Flowers $ without perianth and enclosed in an involucre. 

 Ovary 2-3-celled, with axile placentas, or 1-celled with a central placenta. Mourera, Apinagia, 

 Dicrcea, Podostemon, Hydrobryum, Castelnavia, Tristiclia. 



The affinities of Podostemacea are most obscure. I have suggested that they are reduced forms of 

 Lentibularinece or Scrophularinea. The decidedly dicotyledonous embryo removes them from all the 

 Monocotyledons with which they have been compared. Lindley has suggested Piperacete and Catti- 

 triche, Meissner Ceratophyllea ; more lately Lindley allies them undouhtingly to Elatinece. 



Podostemacece are natives of rocky river-beds in the tropics ; Hydrostachys is Madagascaiian ; Dicraa 

 and Tristicha are Asiatic, Madagascarian, and American. One Podostemon inhabits temperate North 

 America ; the rest of the family are chiefly American, except Hydrobrytim, which is Indian. 



The only known use of the family is that the South American Indians make some use of their saline 

 ashes. ED.] 



1 This order is omitted in the original. Its characters are taken from Tulasne's monograph. ED. 



