COMPOSITAE (COMPOSITE FAMILY) 543 



with dentate margins and often incised or lobed, on long petioles: fruiting 

 involucre about 20-25 mm. long, densely beset with rather long prickles, the 

 2 stout beaks at maturity usually hooked or incurved, the surface and base of 

 the prickles more or less hispid. X. canadense. (X. commune Brit. Man. 

 912. 1901.) A troublesome weed in waste and cultivated ground. 



45. CRASSINA Scepin 



With opposite and mostly entire sessile leaves and single showy heads ter- 

 minating the branches; in ours the leaves are narrow and rigid, connate-sessile 

 and crowded, and the achenes 2-4-aristate. Involucre campanulate or cylin- 

 draceous; the closely appressed-imbricated bracts dry and firm, broad, with 

 rounded summit often margined. Receptacle becoming conical or cylin- 

 draceous; the chaffy bracts conduplicate around the disk-flowers. Lobes 

 of the disk-corolla mostly velvety-villous. Pappus when present of erect awns 

 or chaffy teeth. Zinnia. 



1. Crassina grandiflora (Nutt.) Kuntze, Rev. Gen. PL 331. 1891.. Sca- 

 brous; stems or branches 15 cm. or more high from a stout woody base: leaves 

 linear, 3-nerved at base: involucre narrow, 8 mm. long: ligules 4 or 5, at ma- 

 turity 10-16 mm. long, dilated-obovate or roundish, light yellow or sulphur- 

 color, becoming white. Plains and bluffs; Eastern Colorado to Texas and 

 Arizona. 



46. HELIOPSIS Pers. 



With loosely branching stems, veiny and mostly serrate 3-ribbed leaves on 

 naked petioles, and pedunculate showy heads with numerous yellow rays. 

 Involucre short, of nearly equal oblong or lanceolate bracts. Receptacle from 

 high-convex to conical; the pointless chaffy bracts partly embracing the disk- 

 flowers. ' Ligules large; disk-corollas glabrous. Achenes obtusely 4-angular, 

 with broad truncate summit, wholly destitute of pappus or of 2-4 teeth or a 

 coroniform border. 



1. Heliopsis scabra Dunal, Mem. Mus. Par. 5: 54. 1819. Hispidulous- 

 scabrous, especially the leaves, 5-10 dm. high; leaves broadly ovate and 

 subcordate to ovate-lanceolate, the upper occasionally entire: rays oblong, 

 2-3 cm. in length: achenes smooth, but the angles above pubescent when 

 young, the summit usually bearing an obscure or evident and irregular coron- 

 iform chaffy pappus, or sometimes 2 or 3 conspicuous and rigid teeth. H. 

 laevis. Frequent eastward; rare in the eastern part of our range. 



47. BRAUNERIA Necker 



Perennial herbs, with rather stout erect stems, undivided leaves, the lower 

 long-petioled, and solitary large heads on long peduncles terminating the 

 stem and few branches. Rays flesh-color to rose-purple, elongating with age. 

 Involucre imbricated in 2 or 3 or more series; the bracts lanceolate. Disk at 

 first only convex, becoming ovoid and the receptacle acutely conical; chaffy 

 bracts of the latter persistent, carinate-concave, acuminate into a rigid and 

 spinescent cusp. Disk-corollas cylindraceous, with 5 erect teeth and almost 

 no proper tube. Achenes acutely quadrangular, somewhat obpyramidal, with 

 a thick coroniform pappus more or less extended into triangular teeth at the 

 angles. Echinacea. 



1. Brauneria angustifolia (DC.) Heller, Muhl. 1: 5. 1900. Hispid, 3-5 

 dm. high, mostly simple: leaves broadly lanceolate to nearly linear, entire, 

 3-nerved, all attenuate at base, the lower into slender petioles: bracts of the 

 involucre in orily. about 2 series. Within the eastern limit of our range and 

 extending eastward. 



