444 



COMPOSITAE. 



[Vol.. III. 



72. PSILOSTROPHE DC. Prodr. 7: 261. 1838. 

 [RiDDELLlA Nutt. Trans. .\m. Phil. Soc. (II) 7: 371. 1841.] 



Branched annual or perennial woolly herbs, often nearly glabrous when old, with alter- 

 nate leaves, and middle-sized heads of both tubular and radiate yellow flowers, corymbose, 

 or clustered at the ends of the branches. Involucre cylindraceous, its bracts 4-10 in i series, 

 narrow, equal, densely white-woolly, separate, but erect and connivent, commonly with 1-4 

 scarious ones within, and occasionally a narrow outer one. Rays broad, becoming papery 

 and whitish, persistent, 5---nerved, 2-3-toothed, pistillate. Receptacle small, naked. Disk- 

 flowers perfect, fertile, their corollas with a short proper tube and elongated cylindraceous 

 limb, 5-toothcd, the teeth glandular-bearded. Anthers obtuse and entire at the base. Style- 

 branches of the disk-flowers capitellate. .\chenes linear, striate. Pappus of 4-6 nerveless 

 acute scales, glabrous or villous. 



Three species, natives of the southwestern United States and northern Mexico. 



I. Psilostrophe Tagetinae (Nutt.) 

 Kuntze. Psilostrophe. (Fig. 395S.) 



Kiddellia Tai;etinae Nutt. Trans. ,\m. Phil. Soc. (II) 



7:371. 1841. 

 Psilosliophc Tageltnae Knntze, Rev. Gen. PI. 358. i8gi. 



Perennial, branched, 6'-2° high, loosely white- 

 woolly, or at length glabrous. Basal and lower 

 leaves spatulate, entire, dentate or rarely pinnatifid, 

 mostly obtuse, I'-a/ long; upper leaves sessile, or 

 nearly so, smaller, linear, or spatulate, usually 

 entire; heads several together in the clusters, yi'- 

 \' broad, short-peduncled; rays few, commonly as 

 wide as long, with 2 or 3 broad teeth or lobes at 

 the summit; achenes glabrous, or sparinglj^ pubes- 

 cent; pappus-scales linear-lanceolate to oblong-lan- 

 ceolate, glabrous, shorter than the disk-corollas. 



In dry sandy soil, Kansas and Colorado to Te.xas and 

 Arizona. June-Sept. 



73. FLAVERIA Juss. Gen. PI. 1S6. 1789. 



Glabrous or minutely puberulent, light-green, mostly annual herbs, with opposite sessile 

 entire or serrate leaves, and small i-several-flowered, usually sessile, oblong and densely 

 cymose-capitate heads of tubular, or both tubular and radiate yellow or yellowish flowers. 

 Involucre of 2-5 narrow, nearly equal, appressed bracts, sometimes with i or 2 additional 

 small exterior ones. Receptacle small, naked. Raj'-flower commonly i, pistillate, fertile, 

 sometimes wanting. Disk-flowers 1-15, perfect, fertile, their corollas s-toothed. Anthers 

 entire at the base. Style-branches of the disk-flowers truncate. Achenes oblong or linear- 

 oblong, S-io-ribbed. Pappus none. [Latin, flavus, yellow, from its dyeing properties.] 



.\bout 7 species, natives of the warmer parts of America. In .iddition to the following, 3 others 



occvir in the southern United States. 



I. Flaveria angustifolia (Cav.) Pers. 

 Narrow-leaved Flaveria. (Fig. 3959.) 



Milleria angustifolia Cav. Icon. 3: 12. p!. 22j. 1794. 

 Flaveria angustifolia Pers. Syn. 2: 489. 1S07. 



Annual, glabrous or very nearly so, erect, i°-2°high, 

 little branched. Leaves linear or lanceolate, serrulate 

 or entire, 3-nerved, acuminate or acute at the apex, 

 sessile by a broad and somewhat clasping base, l'-2>^' 

 long, 2"-4"wide; heads about 3" high, closelj' ses- 

 sile in terminal glomerules or these pedunculate from 

 the upper axils; involucre usually of 5 oblong-lanceo- 

 late bracts, 2-5-flowered; ray equalling or longer than 

 the breadth of the disk; achenes linear, glabrous, about 

 iJ<"long. 



In alkaline soil, Kansas and Colorado to Texas, Mexico 

 and New Mexico. .\ug.-Oct. 



