Genus 70.] 



THISTLE FAMILY. 



443 



I. Actinospermum uniflorum (Nutt.) Barn- 

 liart. One-headed Actinospermum. (Fig. 3955.) 



Balduiiia uniflora Xutt. Gen. 2: 175. iSiS. 



A. uniflorum Barnliart, Bull. Torr. Club, 24: 411. 1S97. 



Stem stout, puberulent, simple, or with a few erect 

 branches, i°-3° high. Leaves thick, spatulatelinear or 

 the upper linear, sessile, erect or ascending, i'-2' long, 

 the lower 2"-}," wide; heads loug-peduncled, solitary, 

 j'-a';' broad; bracts of the involucre ovate, acuminate, 

 thick, their tips at length spreading; rays 20-30, cuueate, 

 3-4-toothed at the truncate apex; disk S"-I2" broad; chaff 

 of the receptacle cuncate, truncate, very cartilaginous, 

 more or less united laterally, the summit eroded; achenes 

 obcouic; pappus of 7-9 oblong scales about as long as 

 the acheue. 



In wet pine-barrens, Virginia (according to Torrey and 

 Gray), North Carolina to Florida and Louisiana. July-Sept. 



71. MARSHALLIA Sclireb. Gen. PI. 810. 1789. 



Perennial, often tufted, simple or branched, nearly glabrous herbs, with basal or alter- 

 nate, entire leaves, and large long-peduncled discoid heads of purple pink or white, glandu- 

 lar-pubescent flowers. Involucre hemispheric or broadly campanulate, its bracts in i or 2 

 series, herbaceous, narrow', nearly equal. Receptacle convex or at length conic, chaffy, the 

 scales narrow, rigid, distinct. Rays none. Flowers all perfect and fertile, their corollas 

 with a deeply 5-lobed or 5-parted campanulate limb and a slender tube. Anthers minutely 

 sagittate at the base. Style-branches long, truncate. Achenes turbinate, 5-ribbed and 5- 

 angled. Pappus of 5 or 6 acute or acuminate, ovate or lanceolate-deltoid, nearly entire 

 scales. [Named for Humphrey Marshall, of Pennsylvania, botanical author.] 



Four known species, natives of the southern and central United States. 

 Leaves ovate or oval, or oval -lanceolate, thin, 3-nerved. i. 71/. Irinervia. 



Leaves linear, or the basal spatulale, thick. 2. M. caespitosa. 



I. Marshallia trinervia (Walt.) Porter. 

 Broad-leaved Marshallia. (Fig. 3956.) 



Alhanasia trinervia Walt. Fl. Car. 20i. 178S. 

 Maisliallia lalifolia Pursh, Fl. Am. Sept. 519. 1814. 

 Marshaltia trinervia Porter, Mem. Torr. Club, 5: 337. 



1894. 



Stem simple, or little branched, leafy to or beyond 

 the middle, i°-2° high. Leaves thin, those of the 

 stem ovate, oval, or ovate-lanceolate, 3-nerved, acute 

 or acuminate at the apex, narrowed to a sessile base, 

 2'-3' long, 9"-iS" wide; heads y^'-l' broad, corolla 

 purplish; bracts of the involucre linear-lanceolate, 

 acute, rigid; chaff of the receptacle subulate-filiform; 

 pappus-scales lanceolate-acuminate from a triangular 

 base; achenes glabrous when mature. 



In dry soil, \'irginia to .\labama and Mississippi. 

 May-June. 



2. Marshallia caespitosa Nutt. Narrow- 

 leaved Marshallia. (Fig. 3957-) 



Marsliailia caespitosa Nutt.; DC. Prodr. 5: 6S0. 1836. 



Stems usually tufted and simple, sometimes spar- 

 ingly branched, leafy either only near the base or to 

 beyond the middle, S'-is' high. Leaves thick, faintly 

 3-nervcd. the basal ones spatulate, or linear-spatulate, 

 obtuse, those near the base usually much longer and 

 linear, sometimes 4' long and 3" wide, the upper ones 

 linear, acutish, shorter; head about i' broad, borne on 

 a peduncle often 10' long, corollas pale rose or white; 

 bracts of the involucre linear-lanceolate, acute or acut- 

 ish; chaff of the receptacle linear, or slightly dilated 

 above; achenes villous on the angles; scales of the pap- 

 pus ovate, acutish, equalling or longer than the achene. 



In dry soil, Kansas to Texas. May-June. 



