72 EDTACE*. 



Order XXV. RUTACE/E, 



Represented by a single species of the genus 



PTELEA, Linn. (Hop-Tbee). Shrubs or small trees with alternate 

 3-foliolate aromatic pellucid-dotted leaves, and corymbose regular 

 flowers. Sepals, petals and stamens eaeh 4 or 5, the latter inserted out- 

 side of a disk encircling the ovary. Ovary 2-celled, surmounted by a 

 short style, and becoming an orbicular broadly winged 2-seeded samara 



1. P. crennlata, Greene. Tree 10 —25 ft. high, strongly aromatic when 

 fresh; glabrous except the tomentulose flowers, and a sparse pubescence 

 on the lower face of the leaves and on the fruit: leaflets cuneate-obovate, 

 obtuse or acute, 1 — 3 in. long, crenulate or crenate-serrate: filaments 

 villous near the base: samara % in. long and as broad, truncate or 

 emarginate at both ends, often triquetrous and 3-seeded. — In the Coast 

 Range, from Lake Co. southward through Contra Costa, etc. May. 



Order XXVI. SAPINDACE/E. 



Trees or shrubs with opposite compound, or at least deeply lobed 

 leaves, without stipules. Inflorescence compound, usually racemose or 

 thyreoid. Sepals 5, nearly distinct,' or joined into a tubular calyx. 

 Petals 4 or 5, distinct, and, with the few and definite stamens, inserted 

 hypogynously, or around a hypogynous disk. Fruit a 3-celled capsule, 

 or a double samara. Seeds large; without albumen. 



1. ACER, Pliny (MapijE. Box-Elder). Trees or shrubs with oppo- 

 site palmately lobed or pinnately compound leaves without stipules. 

 Flowers small, greenish or reddish, in terminal racemes, umbel-like 

 corymbs, or fascicles, perfect or unisexual. Calyx usually 5-lobed. 

 Petals 5 or 0. Stamens usually 8 (3—12), in the perfect flowers inserted 

 with the petals upon a lobed disk. , Ovary 2-lobed, 2-celled; styles 2. 



* Leaves simple; tree not dioecious. 



1. A. macrophyllam, Pursh. Tree 50—90 ft. high, 2—3 ft. in diam- 

 eter: leaves V % —\ ft. broad, deeply 5-lobed, the sinuses rounded, the 

 segments often 3-lobed, coarsely toothed: fl. large, in large crowded 

 pendulous racemes which appear with the unfolding leaves, greenish 

 yellow or reddish: stamens 9 or 10; filaments hairy: fruit densely hir- 

 sute or almost hispid, the glabrous wings 1 in. long or more, divergent. 

 — Along mountain streams or on hillsides. 



* * Leaves unequally pinnate; tree diacious. 



2. A. Califoruicum (T. & G.), Dietr. Tree 30—70 ft. high, the young 

 twigs and partly developed leaves villous-canescent : leaflets 3, ovate, or 



