RUTACE^. (RUE FAMILY.) 46 



1. E. cicutarium, L'ller. Ilain, imuh l.nimlKMl from the hase: leaf- 

 lets laciniately itiiiiiiititid wiili narrow atute lohes: jicduncleR exc-ecdinp the 

 leaves: petals briglit rose-color: pediieLs at length n'Mexe<l, the fruit »iill 

 erect. — E. Utah and throughout the whole region west of the K<xkv .Moun- 

 tains. Known as " Alfilaria," " Pin-clover," and " riugrasa." 



3. OX A LIS, I>. WOOIVSOKKEL. 



Low, often acaulescont, with olK-ordatc Icallets and peduncles uuil>ellatelT 

 or cyniosely few to niany-llowered. 



1. O. violacea, L. Aniu/cscnit, ncarlij smooth, leaves and scapes from a 

 scaly hnlh: scapes longer than the leaves, uiubelhitely ilowered : pitals vtolet : 

 capsnJp frir-sfcdeif. — Colorado, and common eastward. 



2. O. COrniCUlata, L. Canlesrcut , more or less villous, from nmniufj root- 

 slocks : stems sometimes 2 or 3 feet high : jutals yd/mv: cd/isuh; many-seeded. 



Var. striata, Sav. WuhoiU stipules. — 0. striata, L. Coloradt) and i-.-isfc- 

 ward across the continent. 



Order 19. R1JTA€Ei£. (Rue Fa.mily.) 



Shrubs or small trees, with pellucid or glaiidular-d(»tted aromatic 

 leaves, definite hypogynous stamens, and few seeds. — Sepals an«l petals 

 4 or 5, imbricated in the bud. Stamens as many or twice as many as the 

 petals, inserted outside of a hypogynous disk. Sti[»ule3 none. 



1. Ptelea. Leaves 3-foliolate. Fruit orbicular, indehiscent, broadly wiiij^ed. Stamens 4 



or 5. 



2. Thainnosma. Leaves simple, alternate. Fruit a 2-lolwd coriaceous capsule. Sta- 



Ilirlis S 



1. PTELEA, L. Shrubby Trefoil. Hop-tree. 



Flowers polygamous. Ovary with a short thick stipe. 2-celled ; cells 2-ovuled, 

 the lower ovule abortive : style short. — Slinihs or small trees; flowers small. 

 greenish-white, in terminal cymes or compound corymhs. 



1. P. angUStifolia, IJenth. A slirnb 5 to 25 feet high, with chestnut- 

 colored punctate liark : leaflets ohlong-lanceolate, entire, hecoming smooth 

 and shining with ag(! : fruit emarginate at hivse and often above; the stipe 

 narrow. — S.Colorado to California and Texas. 



2. THAMNOSMA, Torr. 



Disk cup-shaped, crenate or lohed. Ovary stipitate. 2-celled; cells 5 oi 

 6-ovuled : style elongated. — Low glandular desert shrubs, strongly !*ccnted ; 

 leaves linear ; flowers solitary. 



1. T. Texan a, Torr. Woody only at base, the ."^lender stems 3 to 15 

 inches high : flowers on short naked pedicels : petals yellow tinged with 

 purple. — Rutosma Texanum, Gray. S. W. Colorado and southward. 



