444 



COMPOSITAE. 



[Vol. III. 



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

 [Riddeuja Nutt. Trans. Am. 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 1 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, 5-7-nerved, 2-3-toothed, pistillate. Receptacle small, naked. Disk- 

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

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

 branches of the disk-flowers capitellate. Achenes 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. 3958.) 



Riddellia Tagetinae Nutt. Trans. Am. Phil. Soc. (II) 



7:371. 1 841. 

 Psilostrophe Tagetinae Kuntze, Rev. Gen. PL 358. 1891. 



Perennial, branched, 6 / -2 high, loosely white- 

 woolly, or at length glabrous. Basal and lower 

 leaves spatulate, entire, dentate or rarely pinnatifid, 

 mostly obtuse, 2 / -4 / long; upper leaves sessile, or 

 nearly so, smaller, linear, or spatulate, usually 

 entire; heads several together in the clusters, y 2 f - 

 r/ broad, short-peduncled; rays few, commonly as 

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

 the summit; achenes glabrous, or sparingly pubes- 

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

 ceolate, glabrous, shorter than the disk-corollas. 



In dry sandy soil, Kansas and Colorado to Texas and 

 Arizona. June-Sept. 



73. FLAVERIA Juss. Gen. PI. 186. 1789. 

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

 entire or serrate leaves, and small i-several-fiowered, 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 1 or 2 additional 

 small exterior ones. Receptacle small, naked. Ray-flower commonly 1, pistillate, fertile, 

 sometimes wanting. Disk-flowers 1-15, perfect, fertile, their corollas 5-toothed. Anthers 

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

 oblong, 8-10-ribbed. Pappus none. [L,atin, flavus, yellow, from its dyeing properties.] 



About 7 species, natives of the warmer parts of America. In addition to the following, 3 others 

 occur in the southern United States. 



i. Flaveria angustifolia (Cav.) Pers. 

 Narrow-leaved Flaveria. (Fig. 3959.) 



Milleria angustifolia Cav. Icon. 3: 12. pi. 223. 1794. 

 Flaveria angustifolia Pers. Syn. 2: 489. 1807. 



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' l /t r 

 long, 2 // ~4 // wide; heads about 3 // high, closely ses- 

 sile in terminal glomerules or these pedunculate from 

 the upper axils; involucre usually of 3 oblong-lanceo- 

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

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



V," 



long. 



In alkaline soil, Kansas and Colorado to Texas, Mexico 

 and New Mexico. Aug.-Oct. 



