COMPOSITAE. 1005 



r. rxctmospermum uniflorum (Nutt.) Barnhart. ONE-HEADED ACTING- 



SPERMUM. (I. F. f. 3955-) Stem stout, puberulent, simple, or with a few erect 

 branches, 3-9 dm. high. Leaves thick, spatuiate- linear or the upper linear, ses- 

 sile, erect or ascending, 2-5 cm. long, the lower 4-6 mm. wide; heads long, 

 peduncled, solitary, 5-6 cm. 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 16-25 mrr ' 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, Va. to Fla. and La. July-Sept. 



71. MARSHALLIA Schreb. 



Perennial, often tufted, nearly glabrous herbs, with basal or alternate, entire 

 leaves, and large long -peduncled discoid heads of purple, pink or white, glandular- 

 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 Humph- 

 rey Marshall, of Pennsylvania, botanical author.] About 8 species, of the 

 southern and central U. S. 



Leaves ovate or oval, or oval-lanceolate, 3~5-nerved ; corolla-tube swollen at the throat. 



Stem-leaves ovate to ovate-lanceolate, acuminate. i. M. trinervia. 



Stem-leaves lanceolate to oblong-lanceolate, acute or obtuse. 2. M. grandiflora 

 Leaves linear, or the basal spatuiate, thick ; corolla-tube not swollen at the throat. 



3. M. caespitosa. 



1. Marshallia trinervia (Walt.) Porter. BROAD-LEAVED MARSHALLIA. 

 (I. F. f. 3956.) Stem simple, or little branched, leafy to or beyond the middle, 

 3-6 dm. high. Leaves acute or acuminate at the apex, narrowed to a sessile base, 

 5-7 cm. long, 18-35 mm - wide; heads 1-2 cm. 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, Va. to Ala. and Miss. May-June. 



2. Marshallia grandiflora Beadle & Boynton. LARGE-FLOWERED MAR- 

 SHALLIA. Similar to the preceding species, leafy to above the middle. Lower 

 and basal leaves oblong to oblong-lanceolate, tapering into petioles often as long as 

 the blade, obtuse or obtusish ; upper leaves lanceolate, sessile ; florets slightly 

 larger than those of M. trinen'ia, 1.5-2 cm. long; achenes larger, 4-5 mm. long, 

 pubescent. In moist soil, Penn. to W. Va. and N. Car. July-Aug. 



3. Marshallia caespitosa Nutt. NARROW- LEAVED MARSHALLIA. (I. F. f. 

 3957.) Stems usually tufted and simple, sometimes sparingly branched, leafy 

 either only near the base or to beyond the middle, 2-4 dm. high. Leaves near the 

 base usually much longer and linear, sometimes I dm. long and 6 mm. wide, the 

 upper ones linear, acutish, shorter; head about 25 mm. broad, borne on a pedun- 

 cle often 2.5 dm. long; corollas pale rose or white; bracts of the involucre linear- 

 lanceolate, acute or acutish; chaff of the receptacle linear, or slightly dilated 

 above ; achenes villous on the angles ; scales of the pappus ovate, acutish, equalling 

 or longer than the achene. In dry soil, Kans. to Tex. May-June. 



72. PSILOSTROPHE DC. 



Branched woolly herbs, often nearly glabrous when old, with alternate leaves, 

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

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

 i series, narrow, equal, densely white-woolly, separate, but erect and connivant, 

 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, ^-toothed, the teeth 



