POLYPETALOUS EXOGENOUS PLANTS. 139 



16. AcT^A. Petals 4-8, entire. Ovary solitary, form- 

 ing a many-seeded berry. Floioers in short oblong racemes. 

 Leaves compound. 



17. CiMiciFUGA. Petals 3-5, cleft. Ovaries 1-8, form- 

 ing many-seeded follicles. Racemes elongated. Leaves 

 compound. 



1. ATKAGENE. 



SejMls 4, colored, membranaceous, spreading, valvate in 

 the bud, deciduous. Petals numerous, stamen -like. Sta- 

 mens indefinite. Ovaries numerous, 1-ovuled. Achenia 

 capitate, bearing the persistent styles in the form of long 

 plumose-bearded tails. Seeds suspended. Shrubby vine, 

 climbing by the petioles. Leaves opposite, compound, 

 from scaly buds. Flowers solitary, showy. 



A. Alpina. New Mexico ; April. Bigelow. 



2. CLEMATIS, L. Virgin's Bowee. 



Petals none. Persistent styles, naked or plumose. Other- 

 wise as Atragene. Herbs or shrubby vines. Leaves sim- 

 ple or compound, opposite. Buds not scaly. Flowers 

 solitary or panicled, often polygamous or dicBcious. 



* Flowers solitary, nodding ; calyx thick or leathery. 

 t Stems erect, mostly simple, herbaceous, 

 tt Stems climbing, herbaceous. 



0. VIORNA, L. Smoothish ; leaves pinnate ; leaflets 5-7, 

 oval or oblong-ovate, mostly acute, somewhat membrana- 

 ceous, entire or 2-3-lobed, the lowest pair often tern ate ; 

 calyx ovate ; sepals ovate, tapering into a short recurved 

 point, not margined, rather longer than the stamen ; tails 

 of the achenia {\\' long) plumose. Eiver banks. May- 

 August. Flowers nodding. Sepals thick, reddish purple, 

 1' long. 



C. RETICULATA, "Walt. Smooth ; leaves pinnate; leaf- 



