26 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



DD. BLADES OF THE LEAVES NOT LOBED, THE TEETH ALL EQUAL OR NEARLY SO. 



Leaf blades very asymmetric at the base. • 



Teeth of the leaves obtuse; fruit a woody capsule; flowers appearing in autumn, 



bright yellow; shrubs Hamamelis (p. 172). 



Teeth of the leaves acute; fruit not a woody capsule; flowers appearing in spring or 

 summer; trees or rarely shrubs. 

 Leaves glabrous or nearly so, not rough; flowers appearing after the leaves, their 

 peduncles united with a leaflike bract. Fruit small, indehiscent. 



TILIACEAE (p. 202). 

 Leaves very pubescent or rough; flowers appearing with or before the leaves, their 

 peduncles never united with a leaf like bract. 



Flowers in catkins; fruits arranged in a hoplike strobile Ostrya (p. 137). 



Flowers not in catkins; fruits not in strobiles, either a small winged samara or a 



dru P e TJLMACEAE (p. 140). 



Leaf blades symmetric at the base or nearly so. 

 Leaves evergreen, leathery; plants usually less than 30 cm. high. Flowers with a 

 corolla. 



Fruit a dry capsule; teeth of the leaves not bristle-tipped; flowers in a terminal 



long-stalked cluster; petals distinct Chimaphila (p. 221). 



Fruit a fleshy capsule; teeth of the leaves bristle-tipped; flowers axillary, solitary; 



petals united Gaultheria (p. 222). 



Leaves not evergreen, or, if so, (in Ilex) the plants large shrubs or trees; plants 



usually much more than 30 cm. high. 



Flowers all or mostly in catkins; fruit dry or, if fleshy, a cylindrical multiple fruit- 



(mulberry), never a capsule, sometimes a nut inclosed in a spiny or rough 



bur; flowers appearing with or before the leaves; corolla none. 



Fruit a nut inclosed in a spiny or warty bur. Trees or shrubs; teeth of the 



leaves often bristle-tipped FAGACEAE (p. 137). 



Fruit not a nut inclosed in a spiny or warty bur. 

 Leaves aromatic, conspicuously gland-dotted; fruit a small spheric nut cov- 

 ered with white wax. Leaves oblanceolate; shrubs. 



Myrica (p. 135). 

 Leaves not aromatic and gland-dotted; fruit not wax-covered. 

 Fruit a small capsule; seeds long-hairy. Trees or shrubs, often with large 



stipules SALICACEAE (p. 132). 



Fruit not a capsule ; seeds not hairy. 



Fruit juicy or in spheric heads MORACEAE (p. 141). 



Fruit dry, never in spheric heads BETTJLACEAE (p. 136). 



Flowers not in catkins; fruit often a capsule, never a nut or a multiple fruit- 

 flowers mostly appearing after the leaves; corolla present. 

 Flowers sessile in dense heads on a common receptacle surrounded by an invo- 

 lucre of bracts; fruit an achene, bearing at the top a row of bristles. Corolla 



gamopetaloue; shrubs Baccharis (p. 283). 



Flowers not sessile in dense heads; fruit not an achene. 

 Corolla of united petals; fruit a depressed, 5-lobed or 5-angIed capsule. Flow- 

 ers in simple or panicled racemes; shrubs; stipules none. 



ERICACEAE (p. 222). 

 Corolla of distinct petals; fruit not a depressed 5-lobed capsule. 



Flowers solitary or clustered in the axils. Fruit a berry-like 4-8-seeded 

 drupe; trees or shrubs; leaves sometimes persistent and with spiny teeth. 



AQTTIFOLIACEAE (p. 199). 



