372 RUTACEiE. Choisya. 



first appears) ; Adr. Juss. Mem. Rut. 107 ; Benth. & Hook. Gen. i. 297 ; Baill. 



Hist. PI. iv. 471 (describes the separable eudocarp) ; Morren, Belg. llort. xxx. 



314 t. 17; Gray, Proc. Am. Acad, xxiii. 224, second species added. Juliana, 



Llav. & Lex. Nov. Veg. Desc. ii. 4. — Congener of C. ternata, IIBK., now cult. 



for ornament, is 



C. dumosa, (^kay, 1. c. Much branched, very leafy, 3 to 6 feet high, acrid-aromatic: 

 ' branches glaudular-pustulate : leaflets 3 to 9, uarrowly linear, longer tiiau the petioles (the 

 larger 2 inches long), their margins as if crenately denticulate by coarse glands : petals a 

 third to half inch long: carpels almost separate at maturity, usuaUy only 2 or 3 fertile, 

 ovoid, and with sliort conical cusp ; seed with a deciduous caruncle ? (or attached portion of 

 endoc'arp). — .Is^Vy/""* dumosum, Torr. Pacif. R. Hep. ii. 161, & Bot. Mex. Bound. 42.— 

 Rocky hills, W. borders of Texas (first coll. by Wriyht, without flowers or fruit) and New 

 Mexico to S. Arizona, Bigelow, Schott, Henry, and fine specimens by Pringle. (Adj. Mex. 

 Palmer.) 



3. HELIETTA, Tulasne. {Dr. Helie, a writer on the toxic properties 

 of Rue.) —Ann. Sci. Nat. ser. 3, vii. 280 ; Benth. & Hook. Gen. i. oOl. 't Pi- 

 crella, Baill. Adansonia, x. 149, t. 10. — Two ^ S. American and the following 

 species : — 



H. parvifolia, Benth. Shrub or small tree, glabrous, with slender branches : leaves 

 opposite, palmately trifoliolate ; leaflets cuneateobovate, obtuse, not petiolulate, entire, 

 minutely pellucid-punctate, commonly inch long and middle one larger; petiole sliglitly 

 margined : flowers 4-merous, very small, in terminal and upper axillary cymes, short-pedi- 

 celled : petals white : mature carpels 3 lines long, oblong, the broadly obovate veiny and 

 rather coriaceous wing 4 lines long and broad. — Benth. in Hook. Ic. t. 1385 ; Wats. Proc. 

 Am. Acad. xvii. 33.5.- Ptelea parvifolia, Gray, riiioad Ilemsl. Biol. Centr.-Am. Bot. i. 170, 

 excl. fruit. — Hills near Ringgold, S. W. Texas, Havard. (Adj. Mex., Coahuila, Mondova 

 to Monterey, Berlandier, Gregg, Palmer, Pringle.) 



4. PT^ILEA, L. Hop-tree, Wafer-ash, &c. (Greek name of the elm, 

 transferred to this genus on account of similarity of the fruit.) — Shrubs or small 

 trees (N. American and Mexican) ; with bitter bark and fruit (the samara; used 

 in brewing as a substitute for hops), alternate and pellucid-dotted trifoliolate 

 leaves, and rather small greenish-white flowers in loose terminal cymes ; fl. sum- 

 mer. — Syst. Nat. ed. 1, & Gen. no. 78 ; Adr. Juss. Mem. Rut. t. 26 (42) ; Gray, 

 Gen. 111. ii. 149, t. 157. 



P. pextAndra, Benth. (not DC), PI. Hartw. 14, is apparently sterile Rhns Toxicodendron. 

 There are probably only two genuine species (these very variable and not well distinguishable) 

 and an outlying anomalous one, viz. • — 



P. Aptera, Parry. (Proc. Davenp. Acad. iv. 39, & Bull. Torr. Club, xi. 10.3) a shrub 

 with small leaves (leaflets less than inch long, obovate, subsessile), few-flowered clusters, and a 

 nucumentaceous cartilaginous and turgid fruit (occasionally tricarpellary, half to two thirds inch 

 long), pustulate-glandular, bordered with a very narrow wing, or sometimes wingless ! — All 

 Saints Bay, northern part of Lower California, Parry, Orcutt. So it may be found on the U. S. 

 boundary. 



P. trifoliata, r>. Tall shrub or low tree, strong-scented : leaves puberulent when young, 

 commonly glabrate ; leaflets membranaceous, ovate, mostly acuminate, obsoletely .serrulate 

 or entire (2 to 4 inches long), the lateral sessile and roundish or barely acute and terminal 

 one cuneate-attenuate at base : flowers usually 4-merous : full-grown samara an inch or less 



1 A third S. American species has since been added. 



2 Add Sargent, Silv. i. 81, t. 35. 



8 For further notes on and figure of this species, see Gard. & For. iii. 3-32, f. 45. 



