532 coMPOsiTAE (composite^ family) 



29. LEPTILON Raf. Canada Fleabane 



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

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

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

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

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

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

 brittle hair-Uke bristles in 1 series. 



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

 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 ithe 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 fastigiatei leaves all liarrowly linelar or 

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

 pappus. E. divaricatum. — Possibly ebming into our southeastern border, i 



30. BACCHARIS L. ;i 



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- 

 funnej^form, 5-cleft cproUa; 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 tortubui bristles; those of the 

 I fertile flowers usually more numerous, finer, and cpften elongated in fruit. ' ' 



Herbaceous except at base. - 



Pappus copious, elongating in fruit and siu'passing the style-branches; 



leaves linear, eOftire . .' . . . . ' . ". . XI B, Wrightii. 



Pappus Scanty, scarcely elongating in fruit; leaves elongated-lanceol£ite, - ' 



>' . jgomewhdt serrate . . } . . . -2^ ;B. gluti^osa. 



Shrubs, 1-4 m, high. .i 



Inyoluqral bracts, all acute. . , ' . .' ; 3. B. salicina. 



Involucral bracts obtuse (at least most of them) , ' , '. ' -. 4. B. Emoryi. 



1. Baccharis Wrightii Gray, PI. Wright. 1: 101. 185^. Herbaceous from 

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

 sparsely leaved;,§lpnder branches terminated by solitary heads: leaves Unear, ' 

 small; the uppermbsti 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, scabrousTglandular, 8-10- 

 nerved achene. — Western .Texasito southern .Colorado and Arizona. 



2. Baccharis glutinosa Pers. Syn. .2: 425.|lSd7, Stems herbaceous a^pve 

 but woody toward the base, ;l-3 m. high,- bi;^nches 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 bage, 7-15 cm. long: 

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

 of comparatively simple stems pr branches; involucre, Strajnineous: pappus 

 not very copious or flaccid, and elongated hardly at 9.II in fruit;. E^dnene 

 5-ni6rved. — From southern California to sbuthern Colora,4o ajjd Texas. , 



3. Baccharis salicina T. & G. Fl. 2: 2,58,, .1842. Branching sbr,ub% 1-4 m. 

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

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

 tire: heads or glomerules pedunculate; involucre campanulate, about 6 mm. 

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

 uniserial, conspicuously elongating in fruit, white, soft and flaccid; ^chenes 

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



