Genus 70.] 



THISTLE FAMILY. 



443 



1. Actinospermum uniflorum (Nutt.) Barn- C 

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



Balduina uniflora Nutt. Gen. 2: 175. 1818. 



A. uniflorum Barnhart, Bull. Torr. Club, 24: 411. 1897. 



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



branches, i-3 high. Leaves thick, spatulate-linear or 



the upper linear, sessile, erect or ascendiug, i / -2 / long, 



the lower 2"-$" wide; heads long-peduncled, solitary, 



2 / -2 / I 4 / broad; bracts of the involucre ovate, acuminate, 



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



3-4-toothed at the truncate apex; disk 8 // -i2 // broad; chaff 



of the receptacle cuneate, truncate, very cartilaginous, 



more or less united laterally, the summit eroded; achenes 



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



the achene. 



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

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



71. MARSHALLIA Schreb. 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 1 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. 1. M . trinervia. 



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



i. Marshallia trinervia (Walt.) Porter. 

 Broad-leaved Marshallia. (Fig. 3956.) 



Athanasia trinervia Walt. Fl. Car. 201. 178S. 

 Marshallia latifolia Pursh, Fl. Am. Sept. 519. 1814. 

 Marshallia 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 yi'-i' 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, Virginia to Alabama and Mississippi. 

 May-June. 



2. Marshallia caespitosa Nutt. Narrow- 

 leaved Marshallia. (Fig. 3957-) 

 Marshallia caespitosa Nutt.; DC. Prodr. 5: 680. 1836. 



Stems usually tufted and simple, sometimes spar- 

 ingly branched, leafy either only near the base or to 

 beyond the middle, 8 / -i5 / high. Leaves thick, faintly 

 3-nerved, the basal ones spatulate, or linear-spatulate, 

 obtuse, those near the base usually much longer and 

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

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

 a peduncle often io' 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; a,chenes 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. 



