392 



COMPOSITAE. 



[Vol. III. 



I. Doellingeria umbellata (Mill.) Nees. 

 Tall Flat-top White Aster. (Fig. 3829.) 



Aster umbellatus Mill. Gard. Diet. Ed. 8, No. 22. 176&. 

 Diplopappiisumbellatus'Koo^.. Fl.Bor.Am. 2: 22. 1834. 

 D. umbellata Nees, Gen. & Sp. Ast. 178. 1832. 



Stem glabrous or pubescent above, striate, 

 corymbosely branched at the summit, 2-8 high. 

 Leaves lanceolate, to oblong-lanceolate, ascend- 

 ing, glabrous above, usually pubescent on the 

 veins beneath, membranous, acuminate at the 

 apex, narrowed at the base into short petioles, or 

 the uppermost sessile, hispid-margined, those of 

 the stem 5 / -6 / long, _J^ / -i / wide; heads numerous, 

 6 // -io // broad, in terminal compound corymbs; 

 involucre broadly campanulate or hemispheric, 

 i/^ // -2 // high, its bracts lanceolate, usually pubes- 

 cent or ciliate, acutish or obtuse, imbricated in 3 

 or 4 series, the outer shorter; rays 10-15, white; 

 style-appendages ovate, acute; pappus nearly 

 white; achenes nerved, slightly pubescent. 



In moist soil, Newfoundland to Georgia, west to the 



Northwest Territory, Michigan and Arkansas. July-Oct. 



Doellingeria umbellata pubens (A. Gray) Britton. 



Aster umbellatus van pubens A. Gray, Syn. Fl. 1: Part 2, 197. 1884. 



Under leaf -surfaces pubescent. Michigan to the Northwest Territory. 



2. Doellingeria humilis (Willd. ) Britton. 



Broad-leaved Flat-top White Aster. 



(Fig. 3830.) 



Aster humilis Willd. Sp. PI. 3: 2038. 1804. 

 D. amygdalina Nees, Gen. & Sp. Ast. 179. 1832. 

 Aster umbellatus var. latifolius A. Gray, Syn. Fl. 1: 

 Part 2, 197. 1884. 



Similar to the preceding species, usually lower, 

 seldom over 4 high. Stem striate, corymbosely 

 branched above, glabrous, or somewhat pubescent. 

 Leaves ovate to ovate-lanceolate, rather firm, ses- 

 sile, or the lower very short-petioled, acute or 

 short-acuminate at the apex, narrowed, or some- 

 times rounded at the base, rough-margined, those 

 of the stem \ f -2f long, y 2 '-i' wide, inflorescence 

 as in D. umbellata ; pappus dirty white; achenes 

 somewhat pubescent. 



In moist soil, southern New Jersey and Pennsylva- 

 nia to Florida and Texas. July-Sept. 



3. Doellingeria infirma (Michx.) 



Greene. Cornel-leaved Aster. 



(Fig. 3831.) 



Aster infirmus Michx. Fl. Bor. Am. 2: 109. 1803. 

 Diplopappus comifolius Less. ; Darl. Fl. Cestr. 



474- '837. 

 D. infirma Greene, Pittonia, 3: 52. 1896. 



Stem slender, glabrous, orroughish above, 

 sparingly branched at the summit, terete, 

 i^-3 high. Leaves entire, hispid-mar- 

 gined, glabrous above, sparingly hispid on 

 the veins beneath, the lower obovate, small, 

 obtuse, usually sessile, the upper larger, ob- 

 long-lanceolate, acute, 2 / ~5 / long, x'-y 1 /^ 

 wide; heads few, about i / broad, in a diver- 

 gently branched terminal corymbose cluster; 

 involucre broadly campanulate, 2 // -3 // high, 

 its bracts oblong-lanceolate.obtuse, sparingly 

 pubescent, imbricated in about 4 series, the 

 outer much shorter; rays 8-15, white; style- 

 appendages subulate; pappus tawny; achenes nerved, glabrous. 



In dry, usually rock3' soil, Massachusetts to New York, Pennsylvania and Tennessee. Aug. -Sept. 



