172 



PODOSTEMACEiE. 



PoDOSTEMUM. 



processes, by which the plant adheres to pebbles with great tenacity. Stem 1-4 inches 

 long, terete, smooth, creeping ; the branches erect. Leaves numerous, with stipular processes 

 at the base of the petioles, usually somewhat rigid, varying in length, usually half an inch or 

 an inch long, but in favorable situations 3-5 inches or more. Spalhe cylindrical, at first 

 enclosing and concealing the flower, but finally bursting irregularly at the summit ; the stipe 

 or peduncle included in the spathe, or more or less exserted. Calyx, or involucre, of two 

 subulate flesh-colored leaves, one on each side of the base of the united filaments. Stamens 

 usually 2 ; the lower half or two-thirds of the filaments united into one. Ovary dark green, 

 with 4 strong elevated purple lines on each side : stigmas at first curved towards the stamens, 

 but finally spreading. Capsule oval, ribbed. Seeds numerous, imbricated on the thick placenta. 



At the bottom of shallow pebbly streams. Black River, near Watertown (Dr. Gray) ; 

 stony streams near Newburgh (Mr. Halsted). Fl. July. Fr. August. 



Group 6. Flowers monoecious or dioecious, sometimes furnished with petals as well as 

 calyx, out often destitute of both, not amentaceous. Ovary 2 — several-celled, 

 with one or two ovules in each cell. Fruit capsular or drupaceous, with two or 

 more cells. 



Order XCVI. EUPHORBIACEtE. Juss. The Spurge Tribe. 



Flowers mostly dioecious or monoecious. Calyx 3- or several-cleft (sometimes 

 wanting), often with scaly or glandular appendages. Sterile fl. Stamens 

 one or many, distinct or monadelphous : anthers 2-celled. Fertile fl. Ovary 

 single, 2 — 3- or many-celled : ovules solitary or in pairs, suspended from the 

 inner angle of the cell : stigmas equal in number to the cells, sometimes 

 combined, often 2-cleft. Fruit capsular, separating from the persistent axis 

 into 2, 3 or more cells or cocci, which commonly open elastically by one or 

 both sutures. Seeds very often furnished with a caruncle or arillus. Embryo 

 large, enclosed in fleshy albumen : cotyledons flat. — Herbs, shrubs, or (in 

 warm climates) trees, often with milky acrid juice. Leaves commonly simple, 

 and furnished with stipules. Inflorescence various. 



