COMrOSIT/K 



297 



101. Seneoio. Heads liotproffainnuH and radinto, or Iioniof^nTiions. Disk-i-nrolliiH 5- toothed or 



5-lobed, mostly with slendor tube. Pappus copious, line and soil, white. 



♦ ♦ Leaves mostly opposite or all radical : bristles of the ])ap[)us in a single series, rigid, strongly 



scabrous, barbellate, or plumose. 



102. Arnica. Heafls heterogamous or occasionally homogamous. Pappus scabrous or barbellate. 



Leaves all or some of them opposite. 



103. Ralllardella. Heads honio^ainous. Scales of the involucre sli<;litly united below. Pappus 



strongly plumose, white. Leaves all radical, alternate. 



Tuinr, IX. CYNAROIDK^. Heads homogamous and the (lowei-s all perfect, with corollas 

 all tubular and dee^ily 5-cIeft, often bilabiately so {\ or §), or raicly incompletely dioe- 

 cious, sometimes (in introduced representatives) with a row of neutral flowers at the margin, 

 the corollas of which may be enlarged, forming a kind of false ray. Lobes of the corolla 

 not revolute. Receptacle Generally densely biistly. Anthers sagittate, with their auri- 

 cles often prolonged into tails. Style destitute of all terminal ap[>cndages or tips ; the stig- 

 matic branches either short or slender, but mostly united to the apex or near it, minutely 

 puberulent or granulate : at the origin the style is more commonly thickened into a kind 

 of node or thicKened and often pubescent ring. Akrnes usually thick-walled. Pappus of 

 capillary or rigid bristles. Leaves alternate, the tins or lobes and teeth commonly anned 

 with nnckles. Involucre often of spiny-tipped scales, imbricated in many seiies. — Only 

 Thistles are indigenous to the country, but one or two other genera have been introduced 

 from the Old World. 



♦ Flowers of the head all alike : bristles of the pappus cohering at base in a ring. 



104. Cnicus. Pappus plumose : fdaments sepaiate, papillose-pubescent. 



105. Silybum. Pappus naked : filaments monadelphous, glabrous. Leaves blotched. 



* * Flowers at the margin of the head mostly sterile : bristles of the pappus separate, not plumose. 



106. Centaurea, Akenes attached to the receptacle obliquely or by one side of the base. 



Tiunr, X. MUTISIACE/E. Heads homogamous or sometimes heterogamous, with the limb 

 of the corollas bilabiate (S), one lip 3-, the other 2- toothed or cleft. Receptacle not 

 clothed with bristles. Anthers with long tails. Style-bi-anchcs obtuse or truncate and 

 destitute of any tip or ajipendage. Leaves alternate. — Only one .scanty Californian genus. 



107. Perezia. Hea<l few -many-dowered : the (lowers all perfect and .similar, with distinctly 



2-lipped corollas. Involucre imbricated. Pappus of copious capillary bristles. Akenes 

 beak less. 



TiiiBR XL CICHORIACEiE. Heads homogamous, the flowers all perfect and with lignlate 

 corollas, the ligule 5-toothed at the apex. Style-branches filiform, papillose. Herbs (ex- 

 cept a few insular species) with milky bitter juice. — Tiio aubtrilx-s, not being well-marked 

 by obvious characters, hero give place to artificial .sections. 



♦ Pappus none. All but No. 108 arc genera which ordinarily have a [mppus. 



108. Phalaoroserls. Scape simple: head erect before flowering. Akenes obscurely 4-.'^- 



angled. 



109. Microseris, partly. Scape simple : head nodding before flowering. Akenes 10- ribbed. 

 116. Malacothrix § Anathrix. Scape corymbose-panicled : hpa<ls rather numerous. 



• * Pappus either chaffy or plumose, i. e. of awn-tipped chaffy scales, or of awns or bristles more 



or less dilated into a scale at base, or of plumose i)ristlcs. 



+- Receptacle destitute of chafT or bri.stles : akenes more or less hollowed out at the insertion. 



109. Microseris. Flowers yellow. Akenes 8- 12-ribbcd : pappus more or less chafTy. Stemle.ss 



or short-stemmed and longpeduncled, with head commonly nivlding l)efore flowering. 



110. Stephanomeria. Flowers ]>ink or white. Akenes short, truncate at both ends, about 



5-ribbed or angled : pappus of plumose or partly plumose bristles, or rarely chaffy awns, 

 or narrow scales. Leafy-stemmed and branching, with small heails. 



111. Rafinesqula. Flowers white or pink. Akenes tapering upwards into a narrow beak, 



obscurely ribbed : pappus of cobwebby-plumose slender bristles. Leafy-stemmed and 

 branching, with rather large heads. 

 +■ +- Rocoptado with slender chafT between the (lowers : nkene.s inserted by a pointed Imso : pap- 

 pus of plumose bristles : flowers yellow. 



112. Hypooheerls. Akenes glabrous, the inner ones at least tapering upwartls into a beak : 



{)appu8 sordid or dirty white. 

 BOCOma. Akenes silky-pube.scnnt, tninoato and with a little -rown at the summit : 

 pappus bright white. 



