BLEPHARIPAPPUS 



COMPOSITE 345 



wanting), each subtended by a bract of the usually uniserial involu- 

 lucre which partly or completely encloses its achene. Disk-flowers 

 hermaphrodite, but mostly some or all of them sterile. Receptacle 

 chaffy throughout or of only a more or less united ring between the 

 ray- and disk-flowers. 



* Scales of the receptacle distinct, chaffy-membranaceous or scari- 

 ous, mostly deciduous with the fruit. Bracts of the involucre merely 

 concave. 



46 BLEPHARIPAPPUS Hook. Fl. i, 316 in Part. 



Low corymbosely or paniculately branched annuals with nar- 

 row alternate leaves and rather small heads of white or purplish 

 flowers. Heads heterogamous, with 3-6 pistillate broad-cuneiform 

 3-lobed ray- and 6-12 perfect 5-toothed disk-flowers, or some of 

 the central ones sterile. Bracts of the involucre nearly in a sin- 

 gle series, nearly flat and almost equal. Receptacle convex, 

 chaffy throughout, the chaff thin and membranaceous, deciduous 

 with the fruit. Style in the disk-flowers long, thickened upward, 

 hairy, 2-cleft f only at the apex ; the branches obtuse and not ap- 

 pendaged, or in the central sterile ones nearly entire. Achenes 

 turbinate, silky-villous. Pappus of 10-12 linear or aristiform 

 palea? with hyaline margins which are mostly lacerate-flmbriate 

 so as to appear plumose. 



B. scaler Hook. 1. c. Puberulent and scabrous, and with some hispid 

 hairs above: stems stoutish, 4-12 inches high, loosely branched: leaves 

 linear, sessile. %-2 inches long with entire revolute or involute margins : 

 heads short-peduncled, terminating the paniculate branches: bracts of the 

 involucre lanceolate, acute, 4-5 lines long, more or less hirsute : rays much 

 exceeding the involucre, deeply 3-lobed, always inrolling and becoming 

 inconspicuous when the sun shines on them : anthers brownish-purple. 

 Dry plains and mountains, Brit. Columbia to California and Idaho, east 

 of the Cascade Mountains. 



B. laevis Gray Bot. Gaz. xiii, 73. Stems slender, 6-12 inches high, 

 smooth, branched: leaves linear, 2-10 lines long, sessile, the lower ones 

 spreading, those of the branches closely appressed : heads small, termina- 

 ting the filiform branchlets : bracts of the involucre linear-lanceolate, 2-3 

 lines long, scabrous: rays 3-4 lines long, not closing in sunshine, deeply 

 3-lobed, often with dark-purple veins. On dry plains aud hill-sides, 

 southern Oregon to California. 



* * Scales of the receptacle always present between the ray- and 

 disk-flowers, usually more or less united into a cup. Bracts of the 

 involucre conduplicate-infolded and embracing the laterally com- 

 pressed achenes. 



47 ANISOCARPHUS Nutt. Trans. Am. Phil. Soc. vii, 388. 



Villous-hirsute perennial herbs with linear to lanceolate entire 

 or denticulate sessile leaves and numerous paniculate or corym- 

 bose heads of flowers with yellow rays that do not close in sun- 

 shine. Heads many-flowered; the ray-flowers abont 12, ligulate, 

 pistillate, those of the disk tubular, staminate and pistillate but 



