372 RUTACE^. Choisya. 



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

 Hist. PI. iv. 471 (describes the separable endocarp) ; Morren, Belg. Hort. xxx. 

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

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

 for ornament, is 



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

 branches glandular-pustulate ; leaflets 3 to 9, narrowly linear, longer than the petioles (the 

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

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

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

 &nAoc^v^). — Astrophijllum dumosum, Torr. Pacif. R. Rep. ii. 161, & Bot. Mex. Bound. 42.— 

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

 Mexico to S. Arizona, Bigelow, Schott, Henr;/, and fine specimens by Priinjle. (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. 301. ?Pt- 



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 cuneate-obovate, obtuse, not petiolulate, entire^ 

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

 margined : flowers 4-raerous, 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. 335.^ Pte/ea parvifolia, Gray, quoad Hemsl. Biol. Centr.-Am. Bot. i. 170, 

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

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



4. PTlfiLEA, 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 samarte 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. pentAndra, Benth. (not DC), PI. Hartw. 14, is apparently sterile Rhus 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.^) 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. trif oliata, L. 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 se.s.sile 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. 332, f. 45. 



