Handbook of Teees of the Noetheen States and Canada. 445 



THE SMOKE-TREES. Genus COTINUS Adans. 

 Small trees of two species with aromatic milky juice, one a native of Europe aud Asia 

 and the other of southeastern United States. 



LctticH deciduous, simple, mostly petiolate, thinnish, obovate, obloug or oval, entire, glab- 

 rous or nearly so. Flowers small, greenish-yellow, diu-cious or polygamous, in large loose 

 terminal panicles with slender accrescent pedicels many of which are abortive and become 

 villous: calyx lobes persistent; petals twice as long as the sepals: stamens 5, shorter than 

 the petals : ovary obovoid, compressed ; stj'les 3, lateral, spreading. Fruit 1-seeded dry 

 ■obliquely obloug compressed glabrous drupelets, conspicuously reticulated and bearing the rem- 

 nants of the styles on one side : stone bony. The drupelets occur iu ample loose thyrso'd 

 panicles with many plume-like abortive pedicels. 



The name is the ancient Greek name of the n'ild Olive, transferred to this tree. 

 For species see pp. 30/^-305. 



THE SUMACHS. Genus RHUS L. 



Trees, shrubs and climbing vines of about one hundred twenty species, natives mainly 

 ■of the warmer parts of the north aud south temperate regious. Some are of great economic 

 value, as those producing the lacquer and vegetable wax of Japan, tannin, etc., and several 

 possess poisonous properties. Sixteen or seventeen species are natives of the United States 

 •of which about a half dozen may be considered as trees. 



Leaves lostly unequally pinnate and deciduous, a few simiile and persistent, alternate. 

 Floivers mostly dioecious in compound axillary or terminal panicles: calyx mostly 5-clett or 

 parted and persistent ; petals spreading and longer than the calyx-lobes : stamens 5. alternate 

 with the petals and inserted with them under the margin of the annular disk : pistil solitary, 

 sessile, with three terminal styles. Fruit a subglobose drupelet mostly in thyrses with thin 

 •dry hairy or glabrous outer coat and a single bony or crustaceous stone : cotyledons foliaceous. 



Rhus is the classical Green name of the European Humaeh. 



KEY TO THE SPECIES. 



a. Fruit pubescent, red, with smooth stone, in terminal thyrses 



Rachis of the leaf not winged villose R. hirta. 



Rachis winged between the leaflets R. copallina. 



a' Fruit glabrous, white, with striated stone in axillary panicles R. vernix. 



For species see pp. 306-311. 



HOLLY FAMILY. ILICACE^ Lowe. (AQUIFOLIACE^ DC.) 



Xrees and shrubs with watery sap aud terete branchlets of five genera and about one 

 tiundred seventy species. They are widely distributed in both temperate and tropical regions 

 of both the Old World and the New. Only one genus contains arborescent representatives in 

 the United States. 



Leaves alternate, persistent or deciduous, petiolate, entire, crenate or toothed aud with 

 minute stipules. Floivers small, regular, axillary, white or greenish. dio?cious or polygamous ; 

 calyx with 4-6 lobes imbricated in the bud, generally persistent, hypogenous : petals 4-G, imbri- 

 cated, deciduous, separate or united at base : disk none : stamens as many as the lobes of the 

 corolla, alternate with them and inserted on the corolla ; anthers oblong : pistil solitary, 

 superior, compound with 4-8-celled ovary, short style or none and capitate stigmas of the same 

 number as the cells of the ovary; ovules usually 1 in each cell, suspended, anatropous. Fruit 

 ■a drupe with thin flesh and as many horny or crustaceous nutlets as carpels ; seeds pendulous 

 with minute straight embryo and fleshy albumen. 



THE HOLLIES. Genus ILEX L. 



Trees find shrubs of about one hundred sixty species of which thirteen inhabit eastern 



North America (none the western side of the continent) and five of these are trees. 



The characters are those given of the family. 



The name is the ancient Greek name of the Holly Oak of southern Europe. 



KEY TO THE SPECIES. 



a Leaves evergreen, thick : nutlets ribbed ; leaves. 



Spiny-toothed '• "Paca. 



Entire or remotely serrate i- '•^assine. 



Coarsely crenate I- vomitoria. 



