THISTLE FAMILY 957 



10, the inner 5, usually 3-awned, the outer l-a^voied. H, Thurberi A. Gray. Z). 

 cupulata A. Nels. Z). Thurberi B. L. Robins. Dry hills; Tex.— s Utah— Ariz.; 

 Mex. Mr-N. 



114. PECTIS L. Lemon-scent. 



Rather low^ branching, mostly aromatic or strong-scented, annual or perennial 

 herbs. Leaves opposite, glandular-dotted, mostly entire, usually with several 

 pairs of marginal bristles near the base. Heads usually small, sohtary or cvmose, 

 radiate. Involucre from cylindric or oblong to campanulate or turbinate; 

 bracts 3-12, free, in a smgle series, without calyculum, glandular-dotted, rounded- 

 carinate at least below; receptacle naked. Ray-flowers few, pistillate and fer- 

 tile; ligules yellow or tinged with red or purple. Disk-flowers rather few, hermaph- 

 rodite and fertile; corollas yellow. Style hispidulous, the short branches 

 obtuse and without appendages. Achenes linear, terete or somewhat angled, 

 pubescent or glabrate. Pappus various, of few or many squamellae, awns, or 

 bristles, or rarely reduced to a mere crown. 



bristles. 



B' nappus of a crown of 4 or 5 connate squameUae. sometimes with 1 or 

 ■^f^ 1. P. angustifoha. 



V peduncled: pappus at least of the disk-flowers of 12-18 barbellate 

 ■^ ^ 2. P. papposa. 



1. P. angustifolia Torr. Glabrous annual, lemon-scented; stem branched, 

 5-20'cm. high: leaves narrowly hnear; involucres 4-5 mm. high, 2-3 mm. broad; 

 bracts hnear, about 8; Ugules oblong, about 3 mm. long. P. papposasessihsM, 

 E. Jones. ''Sand-draws" and sandy hillsides: Tex.— ^eb.— Colo.— Ariz.; .Mex. 

 Son . — Mont . ^Ap-0 . 



2. P. papposa A. Gray. Annual, glabrous; stem branched from the base, 

 5-30 cm. high; leaves narrowly Imear, 3-5 cm. long; involucres about 4 mm. high 

 and 3 mm. broad; bracts 7-9, linear; hgules 4-5 mm. long. Sandy places: Cahf. 



Utah— N.M . Son, Au-0. 



115. ACHILLEA (Vaillant) L. Yarrow, Milfoil. 



Perennial caulescent, usually villous, herbs. Leaves alternate, from serrate 

 to tripinnatifid. Heads several, usually radiate. Invo ucre campanulate to 

 hemispheric; bracts imbricate in 3-4 series, the outer usually much shorter. Re- 

 ceptacle conic or convex, chaffy; paleae membranous. Ray-flowers few, ^12, 

 pistillate and fertile; ligules short and broad, m most species white or sometimes 

 pink or purple. Disk-flowers 15-75, hermaphrodite and fertile; corollas yeUow- 

 ish white or straw-colored. Anthers with ovate obtuse tips. Style-branches m 

 the pistiUate flowers oblong, obtuse, in the hermaphrodite ones with trunpate, 

 fimbriate tips. Achenes oblong or obovate, obcompressed, callous-margined, 

 glabrous. Pappus wanting. 



^^^S^Ltt^dar^k iTwTaKst blact margins. 



^"^'^rSaf^se^men'^f of the^^es^^ont not thickened at the apex; 



Ultimate segments of the leaves ovate, lanceolate, or oblanceolate. short, often 



tMcklned at the apex; bracts except the outermost obtuse ; . . 

 Uppe^ leaves 1-2 cm. broad, with spreading not densely f ^^^^^^j^^^/*^^^" 



Upper leaves 5^10 mm. broad, with short densely crowded ^^'^f^' 



\-4 mm. high, about 3 mm. oroaa. , 4, A. subalpina, 



t brown, yeUowish, or straw-colored margins. 



S mm. liigh, 4 mm. broad or more., _ , _^. ^ _,^ 



divisions of the leaves Ime 

 1 with light bro^vn margins 

 divisions 



5. A. californica. 



vellowish or straw-colored. ^ , ^' ^' P(^^n<^^' 



ere 4-4.5, rarely 5 mm. high. 2.5-4 mm. broad., 



imate leaf-segments Unear; rachis merely inargmed. 



Ugules 2.5^ mm. long; leaf-segments ascendmg. crowd^. ^ 



