532 COMPOSITAE (COMPOSITE FAMILY) 



29. LEPTILON Raf. CANADA FLEABANE 



Annual or biennial caulescent herbs. Leaves alternate; blades narrow, 

 entire, or sparingly toothed. Heads small, radiate or discoid. Involucres 

 usually campanulate; bracts several, in 2-3 series. Receptacle naked. Ray- 

 flowers few, pistillate, with short white"? or purplish ligules; disk-flowers 

 several, perfect, the corollas usually with. .4 lobes. Stigmas flattened, with 

 short appendages. Achenes flattened, often pubescent. Pappus of many 

 brittle hair-like bristles in 1 series. 



1. Leptilon canadense (L.) Brit. 111. Fl. 3: 391. 1898. From sparsely 

 hispid to almost glabrous; stem strict, 2-12 dm. high, with numerous narrowly 

 paniculate heads, or in depauperate plants only a few scattered heads: leaves 

 linear, entire, or the lowest spatulate and incised or few-toothed: rays white, 

 usually a little exserted and surpassing the style-branches. (Erigeron cana- 

 dense.) A weed in waste grounds throughout the continent. 



2. Leptilon divaricatum Raf. Fl. Tell. 2: 265. 1818. Low, 1-2 dm. high, 

 diffusely much branched, somewhat fastigiate: leaves all narrowly linear or 

 subulate, entire: rays purplish, rarely surpassing the style-branches or the 

 pappus. E. divaricatum. Possibly coming into our southeastern border. 



30. BACCHARIS L. 



More or less shrubby, with alternate, simple leaves, and the branches 

 striate, bearing small heads of white or yellowish flowers. Heads completely 

 dioecious, many-flowered. Involucre regularly imbricated. Receptacle mostly 

 flat and naked, rarely chaffy. Flowers of the staminate heads with tubular- 

 funnelform, 5-cleft corolla; the pistillate with corolla reduced to a slender 

 truncate or minutely toothed tube. Achenes 5-10-costate. Pappus of the 

 staminate flowers a series of scabrous and often tortuous bristles; those of the 

 fertile flowers usually more numerous, finer, and often elongated in fruit. 



Herbaceous except at base. 



Pappus copious, elongating in fruit and surpassing the style-branches 



leaves linear, entire 

 Pappus scanty, scarcely elongating in fruit; leaves elongated-lanceolate 



somewhat serrate ........ 



Shrubs, 1-4 m. high. 



Involucral bracts all acute ........ 



Involucral bracts obtuse (at least most of them) 



1. B. Wrightii. 



2. B. glutinosa. 



3. B. salicina. 



4. B. Emoryi. 



1. Baccharis Wrightii Gray, PI. Wright. 1: 101. 1852. Herbaceous from 

 a woody base, very smooth and glabrous, 3-6 dm. high, diffusely branching, 

 sparsely leaved; slender branches terminated by solitary heads: leaves linear, 

 small; the uppermost linear-subulate: involucre campanulate, 7-10 mm. high; 

 the bracts lanceolate, gradually acuminate, conspicuously scarious-margined, 

 with a green back: pappus very copious and pluriserial, soft, elongating in 

 fruit, fulvous or purplish, 4 times the length of the scabrous-glandular 8-10- 

 nerved achene. Western Texas to southern Colorado and Arizona. 



2. Baccharis glutinosa Pers. Syn. 2: 425. 1807. Stems herbaceous above 

 but woody toward the base, 1-3 m. high; branches somewhat striate-angled : 

 leaves elongated-lanceolate, serrate with few or several scattered teeth on 

 each side, more or less distinctly 3-nerved from near the base, 7-15 cm. long: 

 heads mostly 6 mm. long, numerous and corymbosely cymose at the summit 

 of comparatively simple stems or branches; involucre stramineous: pappus 

 not very copious or flaccid, and elongated hardly at all in fruit; achene 

 5-nerved. From southern California to southern Colorado and Texas. 



:*. Baccharis salicina T. & G. Fl. 2: 258. 1842. Branching shrubs, 1-4 m. 

 high, glabrous or nearly so, usually viscous, with a resinous exudation: leaves 

 mostly subsessile, oblong to linear-lanceolate, sparingly toothed, rarely en- 

 tire: heads or glomerules pedunculate; involucre campunulate, about (> nun. 

 high; the bracts ovate and aeutish: pappus more or less copious, but mostly 

 unisonal, conspicuously elongating in fruit, white, soft and flaccid; achenes 

 10-nerved. Southern Colorado to Texas and far westward. 



