COMPOSITAE (COMPOSITE FAMILY) 533 



4. Baccharis Emoryi Gray, Bot. Mex. Bound. 83. 1859. Erect, with 

 slender branches, 1-4 m. high: cauline leaves mostly oblong or the lower 

 broader, with attenuate or cuneate base and the larger somewhat petioled, 

 more or less triple-nerved, often with 2-4 short lobes or teeth; those of the 

 branches oblanceolate to linear, mostly entire, 1-nerved: heads somewhat 

 nakedly paniculate on the branchlets, short-pedunculate or the glomerules 

 more or less pedunculate; involucre campanulate or oblong, 5-7 mm. long, 

 mostly of firm coriaceous and obtuse bracts; the outermost oval, the inner 

 oblong, the innermost thin, linear, and acutish. Southern California to 

 Nevada and Arizona, and reported from southwestern Colorado. 



31. FILAGO L. 



Low woolly annuals with small more or less glomerate heads. Receptacle 

 mispherical or conical. Fertile pistillate flowers in 2 sets, the outer set 

 >arated from the inner by a circle of open, scarious or chaff-like nearly gla- 

 >us bracts; flowers of the outer set, which is borne on the margin of the 

 jptacle, commonly destitute of pappus, each loosely infolded by a concave 

 boat-shaped long-woolly bract; flowers of the inner set provided with a 



pappus of copious capillary bristles, not infolded by bracts. Hermaphrodite 



flowers in the center of the head few, often fertile, their pappus abundant. 



Achenes terete or nearly so, either smooth or minutely granular. Evax 



Gaertn. 



1. Filago prolifera (Xutt.) Brit. Mem. Torr. Bot. Club 5: 329. 1894. 

 Rather stout; stem 7-12 cm. high, simple and erect, or with ascending branches 

 from the base, bearing numerous small spatulate leaves and a capituliform 

 glomerule, 10-12 mm. in diameter, whence proceed 1-3 nearly leafless 

 branches similarly terminated; sometimes again proliferous: fructiferous 

 bracts scarious, oval or oblong, mainly naked; those embracing staminate 

 flowers more herbaceous and woolly-tipped, of firmer or more herbaceous 

 texture: staminate flowers each on a filiform stipe representing an abortive 

 ovary. Evax prolifera. Dakota, Colorado, and southward. 



32. ANTENNARIA* Gaertn. 



Dioecious or polygamo-dioecious perennial herbs with alternate leaves and 

 many-flowered heads of inconspicuous flowers. Heads discoid ; the pistillate 

 flowers with filiform truncate corolla shorter than the 2-cleft style ; the stami- 

 nate with tubular 5-lobed corolla and style with undivided truncate apex. In- 

 volucre of imbricated, scarious, persistent bracts, at least their tips white or 

 colored. Receptacle flat or convex, naked. Achenes small, nearly terete or 

 flattish, mostly glabrous. Pappus a single series of capillary bristles, those of 

 the fertile flowers very slender, connate at base, and so falling from the achene 

 in a body; those of the sterile often crisped, mostly thickened at the apex. 



PLANTS SURCULOSE-PROLIFEROUS WITH LEAFY STOLONS 

 Leaves comparatively small, 5-25 mm. long. 

 Tips of involucral tracts green or brown. 



Stems very slender, 2-7 cm. high ...... 1. A. media. 



Stems medium, 8-15 cm. high. 



Leaves broadly spatulate; involucres 6-7 mm. high . 2. A. fusca. 



Leaves spatulate-oblanceolate; involucres about 5 mm. high. 



Leaves obtuse, tomentose . . . . . . 3. A. reflexa. 



Leaves acute, canescent . . . . . . 4. A. umbrinella. 



Tips of involucral bracts not brown or green. 



Heads comparatively small, involucres 5 (4-6) mm. high. 

 Tips of involucral bracts rose-color or rarely whitish. 



Leaves narrowly oblanceolate, acute . . . . 5. A. rosea. 



Leaves spatulate, obtuse . . . . . . 6. A. concinna. 



* The treatment of this genus is largely an adaptation from Prof. Elias Nelson's clear 

 and discriminating revision of a large part of the genus, in Proc. U. S. Nat. Museum 23: 

 697-713. 1901. 



