Order 38.— ANACARDIACE^E. 



283 



excessively pungent in taste. May. — The cone-liko warts on the bark of the 

 larger trees are very curious. 



4. PTELEA, L. Shrub Trefoil. (Gr. TrreXea, the elm tree ; from 

 the resemblance of the fruits.) ? £ $ . Sepals 3 to 6, mostly 4, much 

 shorter than the spreading petals ; t stamens longer than the petals 

 and alternate with them, very short and imperfect in ? ; ovary of 2 

 united carpels ; styles united, short or ; stigmas 2 ; fruit 2-celled, 2- 

 seeded samara?, with a broad, orbicular margin. — Shrubs with 3 to 5- 

 foliate lvs. Fls. cymous. 



P. trifoliata L. Lvs. 3-foliate, lfts. sessile, ovate, short-acuminate, lateral ones 

 inequilateral, terminal ones cuneate at base ; cymes corymbous ; stam. mostly 4 ; 

 sty. short. — Au ornamental shrub, 6 to Sf high, West. States, rare in W. N. York. 

 Lfts. 3 to U' by 1J to If, the ped. rather longer. Fls. white, odorous, nearly £' 

 diam. Samara nearly 1' diam. 



5. AILANTUS, Desf. Chinese " Tree-of-Heaven." (From the 

 Chinese name, Ailanto.) ? £ $ Sepals 5, more or less united at base; 

 petals 5 ; § stamens 2 to 3 ; ovaries 3 to 5; styles lateral ; fruit 1- 

 celled, 1-seeded samara?, with oblong margins; $ stamens 10 ; $ ova- 

 ries, styles and samara? as in £ . — Oriental trees and shrubs with pin- 

 nate lvs. Fls. in panicles. 



A. glandulosa Desf. Lvs. glabrous, unequally pinnate, lfts. ovate or oblong- 

 lanceolate, acuminate, shortly petiolate, with one or two obtuse, glandular teeth 

 each side at base, terminal one long-petiolate. — A tree of large dimensions, and 

 with luxuriant foliage. Trunk straight, with a smooth, brown bark. Lvs. 3 to 

 5f in length, with 10 to 20 pairs of leaflets, and an odd one. Fls. in terminal 

 panicles, green, very ill-scented, rendering the tree a nuisance when in bloom 

 (May and June). The rapid growth of this tree is its only recommendation as a 

 tenant of our parks. 



Order XXXVIII. ANACAKDIACILF. Sumachs. 



Trees or shrubs, with a resinous, gummy, caustic, 

 or even milky juice. Leaves alternate, simple or 

 ternate, or unequally pinnate, without pellucid 

 dots. Fls. terminal or axillary, with bracts, com- 

 monly dioecious, small. Sepals 3 to 5, united at 

 base, persistent. Petals of the samo number, 

 (sometimes 0), imbricated. Stamens as many as 

 petals, alternate with them, distinct or coherent, 

 and pcrigynous. Ovary 1-celled, free. Ovule one. 

 Styles 3 or 0. Stigmas 3. Fruit a berry or drupe, 

 usually tho latter, and 1-seeded. Albumen 0. 



Genera 49, species 100, chiefly natives of tropical 

 regions, represented in the U. S. by the genus Khus 

 only. 



Properties. — These plants abound in a resinous juice, 

 ■which is poisonous, but is used as an indelible ink in 

 marking linen, and as an ingredient in varnish. Even 

 the exhalations from some of the species are deemed 

 poisonous. The Cashew nut is the product of a small tree of both Indies. When fresh the ker- 

 nel is full of a milky juice, and has a most delicious taste, but the coats are filled with a caus- 

 tic oil which blisters the skin and kills warts. 



RHUS, L. Sumac. (The ancient name, from Celtic, rhudd, red ?) 

 Calyx of 3 sepals united at. base ; petals and stamens 5 ; styles 3, stig- 

 mas capitate ; fruit a small, 1-seeded, subglobous, dry drupe. — Small 



631, Rhus, leaf and panicle. 2. A stam- 

 iiiaie flower. 3. Section of a fertile flower. 



