246 GENUS ATRIPLEX. 



Artificial Key to the Species of A triplex — Continued. 

 Bracts more or less compressed except when under 4 mm. long; 

 seed 1.5 mm. or less long. 

 Fruiting bracts exactly orbicular, toothed all around. Desert 



annual 26. A. elegant (p. 300). 



Fruiting bracts cuneate-orbicular to obovate, entire near the 

 base. 

 Inflorescence of staminate glomerules 5 to 30 cm. long. 

 Plant annual; leaves mostly dentate. 

 Leaves broadest above the middle, lower surface white. 28. A. wrighli (p. 304). 

 Leaves broadest below the middle, lower surface greenish. 29. A. bracteosa (p. 305). 



Plant perennial; leaves all entire 30. A. linifolia (p. 308). 



Inflorescence of staminate glomerules 3 cm. or less long, or 

 flowers all axillary. 

 Length of fruiting bracts 1 to 2 mm. Pacific Coast annual 



with entire leaves 27. A. mierocarpa (p. 303). 



Length of fruiting bracts 2.5 mm. or more. 



Fruiting bracts globoid, not compressed. CaUfornian 



perennial 31. A. frutieruloaa (p. 309). 



Fruiting bracts obovate, compressed but sometimes 

 thickened by numerous appendages. Forms of the 

 Californian A. bracteosa with reduced staminate 

 inflorescences might be sought here, but distin- 

 guished by its evil odor and from No. 32 by the 

 dentate leaves. 

 Branches erect or spreading but always with erect or 

 ascending ends, thickish, from an annual or her- 

 baceous-perennial base; leaves entire or toothed, 

 commonly larger than in the next, often obtuse. 

 Mexico and Texas to the West Indies and New 



England 25. A. pentandra (p. 294) 



Branches mostly prostrate at least at first, slender, 

 from a short woody perennial base; leaves all entire, 

 1 to 2 cm. long, 0.2 to 0.4 cm. wide, acute. Cali- 

 fornian coast 32. A. coulteri (p. 310). 



Pistillate and staminate flowers on separate plants; leaves chiefly 



opposite 34. A. matamorensis (p. 312) . 



(Here might be sought also nuttalli, corrugata, obo- 

 vata, and acanthocarpa, all dioecious subshrubs with 

 alternate leaves. See under next heading.) 

 Plant a shrub or subshrub. 

 Bracts never with 4 conspicuous longitudinal wings. (Irregular flattened appen- 

 dages are not to be mistaken for wings.) 

 Plant not spiny. 



Mature bracts 4 to 8 mm. or more long, either narrower or broader than long. 

 Margin of leaf entire or only undulate. 

 Leaves narrowed at base, 0.5 to 3.5 cm. long, or longer. 



Tall shrubs, 10 to 30 dm. high; bracts orbicular 43. A. lentiformis (p. 334). 



Low shrubs, 1 to 10 dm. high; bracts never exactly orbicular. 

 Bracts longer than broad. 



Bracts lanceolate to elliptic or cuneate-oblong, entire or toothed at 



summit 38. A. nuttalli (p. 322). 



Bracts narrowly fan-shaped, ending above in a broad free transverse 



lobe 39. A. corrugata (p. 330). 



Bracts broader than long 37. A. obovata (p. 321). 



Leaves sagittate-clasping, 0.2 to 0.4 cm. long 41. A. julacea (p. 333). 



Margin of leaf dentate. 



Bracts globoid, not compressed 36. A. acanthocarpa (p. 320) 



Bracts orbicular, strongly compressed 42. A. hymenelytra (p. 333). 



Mature bracts 2 to 4 mm. long, about as broad as long or broader. 

 Leaves medium-sized or large, 0.5 to 5 cm. wide, 1 to 5 cm. long. 



Stems herbaceous above; bracts not truly orbicular. Mexican 35. A. barclayana (p. 313). 



Stems woody throughout; bracts orbicular 43. A. lentiformis (p. 334). 



Leaves small, 0.2 to 0.4 cm. wide, 0.3 to 1.5 cm long (longer only on sterile 



shoots) 40. A. polycarpa (p. 331). 



Plant spiny, the spines consisting of slender rigid sharp-pointed twigs from which 

 the leaves or fruiting bracts have fallen. 

 Bracts orbicular, or broader than long in one form with wing-angled twigs. ... 43. A. lentiformis (p. 334). 

 Bracts not orbicular; the twigs terete or obtusely angled. 

 Leaves not cordate at base; bracts 6 to 15 mm. long. 



Body of bract small, not contracted beneath the free terminal wings; 



leaves strictly entire 44. A. confertifolia (p. 338). 



Body of bract large, thick, contracted to a neck beneath the free terminal 



wings; some of the leaves subhastat* at base 45. A. spinifera (p. 340). 



Leaves cordate at base; bracts 3 to 4 mm. long 46. A. parryi (p. 341). 



Bracts with 4 conspicuous longitudinal wings extending the whole length of the 



body and often beyond 47. A. canescens (p. 342). 



