160 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



4. Thalictrum dasycarpum Fisch. & Lall. 



Woods and thickets; frequent. May-July. Eastern U. S. (T. purpurascens of 

 Ward's Flora, in part.) 



5. Thalictrum caulophylloides Small. 



Low ground along the upper Potomac; common. May-June. Md. to Tenn. (T. 

 purpurascens of Ward's Flora.) 



12. CLEMATIS L. 

 1. Clematis virginiana L. Virqin's-bower. 



Marshes or thickets along the Potomac and Eastern Branch; occasional. Aug.- 

 Sept. Eastern N. Amer. 



Clematis paniculata Thunb. is reported to have escaped at several localities about 

 Chevy Chase (E. T. Wherry). Native of Japan; widely cultivated. Distinguished 

 from C. virginiana by having more than 3, entire leaflets. 



13. VIORNA Reichenb. Leather-flower. 



Plants erect; leaves sessile or nearly so, simple, entire 1. V. ochroleuca. 



Plants climbing; leaves petioled, compound, composed of 3 or more leaflets, Ihese 

 often lobed 2. V . viorna. 



1. Viorna ochroleuca (Ait.) Small. 



Wooded hillsides along the Virginia side of the Potomac; occasional. Apr. -May. 

 Staten Isl., N. Y., to Ga. (Clematis ochroleuca Ait.) 



2. Viorna urnigera Spach. 



Woods and thickets along the upper Potomac; frequent. June. Pa. to Ind. and 

 Ga. (Clematis viorna L.; V. viorna Small.) 



59. BERBERIDACEAE. Barberry Family. 



Leaves pimple, deeply lobed, the blades peltate (the petiole not attached at the base 

 of the blade but above the base). Plants with 2 leaves at the top of a stout stem, 

 a single large white flower borne between the leaves; fruit yellowish green, about 



5 cm. long, pulpy 1- PODOPHYLLUM. 



Leaves compound, of 2 or more leaflets, never peltate. 

 Leaflets 2, entire; leaves all basal; flowers solitary, on long scapes, white, showy; 



fruit a capsule, opening by a lid 2. JEFFERSONIA. 



Leaflets more than 2, coarsely lobed; leaves partly borne on the sterna; flowers in 

 small panicles, small, purplish green; fruit fleshy, blue. .3. CAULOPHYLLUM. 



Berberis vulgaris L., the barberry, has been collected as an escape at two or three 

 stations within our range. Native of Eur.; commonly cultivated and sometimes 

 escaping. Several other species of Berberis (with simple leaves) and of the closely 

 related genus Odostemon (with pinnate leaves) are frequent in cultivation. 



1. PODOPHYLLUM L. 



1. Podophyllum peltatum L. • May-apple. 



Woods and thickets; common. Apr.-May; fr. July. Eastern N. Amer. 



Known also as mandrake. The large fruits are edible. The roots are used in 

 medicine. The flowers are shown in plate 26. 



2. JEFFERSONIA Barton. 



1. JefTersonia diphylla (L.) Pers. Twin-leaf. 



Islands of the Potomac; rare, but locally abundant. Apr. N. Y. to Iowa and 

 Tenn. 



The genus was named in honor of Thomas Jefferson. Plants in flower are shown in 



plate 28B. 



