20. Aster Eulae Shinners. 



Rhizomatous perennial; stem erect and with many ascending or spreading 

 branches; head-bearing branchlets mostly 1-3 cm. long, usually somewhat secund; 

 leaves membranous; midstem leaves several cm. long (quite variable in size), 

 usually elliptic to oblanceolate but in their basal third broadly cuneate, usually 

 obscurely serrate; leaves in the upper branches similar in shape but smaller, 

 usually 15-30 mm. long, 3-6 mm. broad; leaves of the head-bearing branchlets 

 linear or linear-lanceolate, not crowded, 3-10 mm. long, about 1-2 mm. broad; 

 involucres hemispheric, 4-5 mm. high, of a few series of well-graduated phyllaries, 

 the shortest of which are about a third or even only a fourth as long as the 

 longest; rays 20 to 30, about 4 mm. long, usually white but less commonly bluish- 

 white; mature disk corollas (4.1-) 4.5-5 mm. long, with a tube 1.3-2.2 mm. long, 

 plus a throat 1.3-2.5 mm. long, plus lobes 0.5-0.9 (-1.1) mm. long. 



Frequent in usually heavy clay or clay-loam soil, ditches, banks and openings 

 in river bottom woods, n.-cen. Tex., infrequent to the s. part of e. and s.e. Tex., 

 perhaps as far s. as Nueces Co., Oct.-Nov.; endemic. 



12. Doellingeria Nees 

 A monotypic North American genus. 



1. Doellingeria umbellata (Mill.) Nees var. latifolia (Gray) House. 



Rhizomatous perennial; aerial stems simple for most of their length, rising at 

 intervals from the rhizome, to 1 m. high; leaves alternate, the lowest leaves (near 

 ground level) actually smaller than those of the midstem, there being an increase 

 in size of the leaves proceeding up the lowest part of the stem; leaves in general 

 ascending or appressed, narrowly ovate-elliptic or broadly lanceolate, several cm. 

 long or reduced in the head-bearing region; upper 3-20 dm. of the plant 

 branched, the branches erect and forming a dense corymbiform grouping of 

 heads, each head on a short erect peduncle 3-10 mm. long; involucres about 4 

 mm. high, of perhaps 3 series of strongly graduated mostly stramineous phyllaries 

 with unexpanded or only very slightly expanded green midribs; rays 2-3 mm. long, 

 whitish; disk yellow; pappus slightly double, of very unequal capillary bristles, 

 alike in disk and ray. Aster umbellatus Mill. var. latifolius Gray. 



Rare in wet usually boggy ground, in Okla. (McCurtain Co.) and in e. Tex. 

 (Bowie, Freestone and Nacogdoches cos.), Sept.-Oct.; the species as a whole 

 occurs in s.e. Can. and e. U.S. s. to N.C., Ga., Tenn. and w. to Minn., la., Ark. 

 and Tex. 



13. Erigeron L. Fleabane 



Herbs, usually pubescent; leaves alternate, essentially sessile (the blades often 

 narrowed to subpetiolar bases); heads solitary, terminating ascending branches 

 which are often somewhat pedunculiform; involucres usually hemispheric, usually 

 3-8 mm. tall; receptacle flat or often convex, essentially smooth; phyllaries in 

 only about 2 or 3 series, not or only weakly graduated, usually lance-subulate, 

 acute, mostly herbaceous with very narrow scarious margins; ray flowers present, 

 usually in about 2 series, pistillate, fertile; rays linear, white or pale shades of 

 bluish or rose, never yellow; disk flowers perfect and fertile (except sometimes 

 a few central ones abortive); corollas yellow, with a very short basal tube and 

 a slightly broader subcylindric 5-toothed limb; achene laterally flattened, strongly 

 2-ribbed (or the extreme peripheral ones often 3-ribbed), nearly glabrous; pappus 

 various, either essentially absent or a paleaceous crown or of fragile capillary 

 bristles and short scales or usually of unequal capillary bristles, these often in 

 2 size-classes (the pappus then said to be "double"). 



1626 



