COMPOSIT.E. 71 



Subtribe II. Eiddellie.i:. Involucre of narrow equal erect bracts. Ligiiles i^ersistent 

 and becumii.g papery on the usually striute-nerved akuues. Heibag,; moie or less 

 white-woolly : no oil-glands. 



* Pappus paleaceous : rays very broad, few. 



131. RIDDELLIA. Heads witli 3 or 4 ray- and .'> to 1-' disk-flowers, all fertile. Involucre 

 Lyliudraceoas-iaiupauulate. of 4 to 10 linear-oblong loriateous woolly bracts, and a few 

 smaller sravious ones within, sometimes an additional narro\\- outer one. liuceptacle small, 

 flat. Ligules as broad as long, abruptly contracted at ba-e into a short tube, truncate and 

 2-3-lobed. j-7-iierved, the nerves uniting in pairs within the lobes. l)isk<-orollas elonitated- 

 cylindraceous, with very short proper tube, and .^hort externally glandular-bearded teeth. 

 Myle-branches truncate-capitate. .Vkenes narrow , terete, [■bsum-ely striate or angled. Pap- 

 pus of 4 to S hyaline nerveless and pointless palefe. 



* * Pappus none : rays several or numerous ; disk-flowers numerous. 



132. BAILEYA. Involucre hemispherical, of numerous thin-herbaceous linear bracts in 

 ■2 or 3 scries, very woolly on the back. Receptacle flat or barely convex. Rav-flowers 

 5 to 50; the ligules from round-oval to oblons-inui-.ue, 3-toothed at apex, 7-nerved, taper- 

 ing into a narrow but not tubular base, becoming scarious-papery but tbm, persisteut on the 

 truncate summit of the afcene. Disk-flowers fertile ; their corollas tubnlar-fuunelform above 

 the short proper tube, 5-toothed ; the teeth glandular-bearded. Style-branches short, with 

 trmicate-capitate tips. Akenes oblong-Unear or clavate, somewhat angled, pluricostate or 

 striate ; the truncate apex obscurely toothed by extension of the ribs, or in the rai' callous- 

 thickened. 



133. "WHITNEYA. Involucre campauulate, of 9 or 12 oblong or broadly lanceolate 

 equal thin-herbaceous bracts, nearly in a single series, in fruit somewhat cymbiform-cari- 

 nate near the ba.*e, not villous. Receptacle narrow-conical, vUlous. Rav-flowers 7 to 9 ; 

 ligule elongated-oblong, minutely 3-toothed at apex, 10-16-nerved (the nerves also prominent 

 on the short tube), becoming thin-papery, persistent. Disk-flowers numerous, infertile, the 

 tubular-fimuelform obtusely 5-toothed corollas persistent on the sterile akenes : srvle-branehes 

 linear, pubescent externally, with rather obtuse tips. Ray-akenes only maturing, oblong, 

 sUghtly obcompressed. obtuse at both ends, lightly nerved. 



Subtribe III. Perityle.1:. Involucre of equal and narrow erect bracts, in only one or 

 two series. Ray-flowers female or none ; the ligule deciduous ; disk-corollas narrow, 

 4-toothed. Akenes flat, with only mai-ginal callous nerxes, usually much ciliate. 

 St}le-branches and their appendages slender. Receptacle flat or convex. Plants not 

 floccose-tonientose. and with no oil-glauJs. (Uuhia. 154, might be sought here. 

 Eatonelhi, 137, and VroclLcria, 137^, also have flat and ciliate akenes with strong mar- 

 ginal nerves.) 



134. LAPHAMIA. Head sexeral- to many-flowered. Bracts of the hemispherical invo- 

 lucre distinct, more or less overlapping- biyle-tiii? ^ct;lceous subulate, hirsute. JIargin of 

 akenes naked or not much cUiate. Pappus none, or of one or two, or sometimes about 20 

 bristles. SufEruticulose perennials, or lieruaceoiis from a thick woody base, mostly yellow- 

 flowered. 



135. PERITYLE. Head many-flowered. Involucre of preceding, or the bracts more cari- 

 nate-concave and partly embracing outer akenes. Style-branches with either short (acute 

 or obtuse) or slender hirsute tips Akenes at maturity cartilaginous-margined, usually 

 strongly ciliate. Pappus a squamellate or cupulate crown, and commonly a slender awn 

 from one or botli ;ingles. ^Mostly aimuals, white- or yellow-flowered. 



136. PER.ICOME. Head many-flowered, homogamotis. Involucre a strictly single series 

 of numerous narrow bracts, which are lightly connate by their edges iuto a campanulate 

 cup. Disk-corollas slender, with ^ iscous-glandular tube nearly the length of the cylindrical 

 throat, from which the anthers ;\re much exseitiJ Sryle-tips filifoim, rather obtnse. 

 Akenes strongly villoa?<'iliate. Pappus a spiamellate lacerate-cUiate crown, and scmerimes 

 a pair of short awns, one from each angle of tlie akeue. Perennial, yellow-flowered, with 

 long-actmiiuate leaves. 



