Hemizonia. COMPOSITE. 361 



slightly hairy ; those of the ray obovate-oblong and obcorapressed, tipped with a 

 short inflexed beak. Hemizonia (Hemizonella) Durandi, Gray, 1. c. Harpcecar- 

 pus madarioides, Durand, not of Nutt. 



Dry hills, common through the foot-hills and the Sierra Nevada from Mariposa County north- 

 ward, and in Nevada. 



3. H. minima, Gray, 1. c. An inch or two high : leaves half an inch or less in 

 length ; the uppermost equalling or barely surpassing the short-peduncled or almost 

 sessile heads : akenes obovate, decidedly obcom pressed, glabrous or nearly so, tipped 

 with an inflexed apiculation, but not beaked. Hemizonia (Hemizonella) minima., 

 Gray, 1. c. 



Dry sterile soil in the Sierra Nevada : Soda Springs, Brewer. Between Nevada Fall and Cloud's 

 Rest, Gray. 



57. HEMIZONIA, DC., Torr. & Gray. TARWEED. 



Head many few-flowered, heterogamous, with 1 to 20 pistillate rays ; the disk- 

 flowers several or numerous, hermaphrodite but usually all and always the central 

 ones infertile. Involucre of as many scales as ray-flowers, which are concave and 

 half enclosing their turgid akenes, or sometimes a few loose and empty outer ones. 

 Receptacle flat or conical, chaffy only between the ray- and disk-flowers, or through- 

 out. Rays 2 - 3-toothed, cleft, or parted : disk-corollas funnelform, 5-lobed. Akenes 

 of the ray turgid, more or less gibbous, obovoid and often triangular, commoidy 

 minutely stipitate ; those of the disk, when formed, narrower and seldom truly 

 fertile. Pappus none in the ray, or in one species rudimentary ; either none or of 

 several chaffy scales or awns in the disk. Annuals or biennials, some with indu- 

 rated stems, and one frutescent, all Californian, mostly glandular and viscid, heavy- 

 scented : some of them are Tarweeds or Rosin-weeds of the Californians. Leaves 

 narrow, all but the lowest alternate : heads middle-sized or small; the flowers yel- 

 low or white, with brownish anthers. Benth. & Hook. Gen. PI. ii. 394 ; Gray, 

 Proc. Am. Ac. ix. 190. Hemizonia, Hartmannia, & Calycadenia, DC. Osmadenia, 

 Nutt. Hemizonia & Calycadenia, Torr. & Gray. 



1. Fertile akenes very oblique, the small terminal areolafrom the summit of the 

 inner angle or face on a narroio beak or apiculation ; the surface dull, often 

 rugose or tuberculate : flowers yellow. HARTMANNIA, Gray. 



* Receptacle flat or nearly so, chaffy only between the ray- and disk-flowers ; the chaff 

 mostly united into a cup or internal involucre : heads small or middle-sized : akenes 

 of the ray rugose or somewhat tuberculate when mature, inserted by a short and 

 thickish incurved stipe : disk-akenes all sterile and mostly abortive, usually bearing a 

 pappus of small scales. (Hartmannia, DC.) 



-i- Rays and disk-flowers few or several ; the former with tube thickish at base ; the 

 latter ivith conspicuous pappus of chaffy lacei-ate-toothed scales : heads comparatively 

 small, bracteate, mostly sessile or fascicled : scales of the involucre lanceolate, more 

 or less carinate toward the base. 



++ Perennial and woody, exceedingly leafy : rays about 8. 



1. H. frutescens, Gray. Erect, 2 feet or more high, decidedly shrubby, with 

 numerous fastigiate flowering branches very leafy to the top, hirsute, aromatic and 

 viscid : leaves filiform, and with tufts of shorter ones in the axils, entire, or rarely 

 with one or two short lateral lobes : heads thyrsoid-racemose : involucre nearly gla- 

 brous : rays 8 or 9 ; the ligules obovate-oblong, 2 - 3-toothed, about the length of 



