Ebigeron. COMPOSlTiE. 175 



§ 4. Rays very numerous, nearly or quite in a single series, longer than the 

 involucre: paiypus mamfeslly double; the exterior very short, subulate or 

 squamellate, or almost coroniform ; the interior of few somewhat deciduous 

 bristles, often caducous or tcanting in the ray : achenia 2-nerved : annual 

 or biennial.— Fhalacko-loma, Cass. (Stenactis, DC. partly, excl. char.*) 



* Pappus of the ray and disk similw. (Erigeron § Oligotrichium, NiUt.) 



25. E. tenue : branched from the base, minutely strigose or scabrous ; 

 stems slender, ascending or erect, bearing few (1-9) small heads on slender 

 peduncles ; leaves short, with minutely ciliate and scabrous margins ; the 

 radical ones spatulate-oblong, somewhat lyrately toothed or sparingly lobed, 

 on slender petioles; the lower cauline mostly oblong-linear, entire; rays 

 very narrow and numerous, twice the length of the almost glabrous involu- 

 cre; inner pappus of 12-20 rather fragile bristles. — E. quercifolium, {Nutt.!) 

 DC. ! j^rodr. 5. p. 285, certainly not of Lam. 



Prairies, and banks of rivers, Arkansas, Nuttcdl ! Louisiana, Dr. Car- 

 penter ! Dr. Hale! Dr. Leavenworth ! Texas, Drumiytond .' April-June. — 

 (D or II ? Stems slender, 5-10 inches high, pubescent near the base. 

 Leaves somewhat glabrous, the lower about an inch long. Heads smaller 

 than in E. quercifolmm, when several in number somewhat corymbose ; the 

 peduncles slightly thickened at the summit. Rays purplish, very slender, 

 more than 100 in number, but nearly or quite in a single series. Inner pap- 

 pus similar in the disk and ray, of 12 to 20 slender rather fragile scabrous 

 bristles ; the exterior very tnanifest, setaceous-squamellate, much shorter 

 than the slightly pubescent achenia. 



26. E. diver gens: somewhat hoary with a minute hirsute pubescence, 

 diffusely branched from the base ; leaves small', entire, acute ; the radical 

 somewhat spatulate, narrowed into a short petiole ; the cauline scattered, 

 sessile, linear, narrowed at the base ; heads (small) mostly solitary termina- 

 ting the naked branchlets or peduncles ; rays very narrow and numerous, 

 twice the length of the hirsute involucre; inner pappus of few (8-12) very 

 slender and deciduous bristles. — Erigeron (Oligotrichium) divaricatum, Nutt. ! 

 in trans. Amer. phil. soc. {n. ser.) 7. x>- 311, "ot ai Michx. 



Rocky Mountains, and plains of the interior of Oregon, Nuttall! — (l) 

 Stems about a foot high, diffiise, ascending, slender, at length much branched. 

 Leaves half an inch to an inch long, 1 to 2 lines wide, mucronate-acute. 

 Heads rather smaller than in E. tenue ; tire rays (white, Nutt.) nearly simi- 

 lar ; the exterior pappus shorter. 



* * Imier pappus of the ray almost or entirely vxmting. (Phalacroloma, Cass. , proper.) 



27. E. annuum (Pers.) : sparsely hirsute or hispid with more or less 

 spreading hairs; stem corymbosely branched above; leaves coarsely and 

 sharply serrate-toothed ; the radical and lowermost ovate, obtuse, tapering 

 into a margined petiole ; the others ovate-lanceolate, sessile, acute and entire 

 at each end ; the uppermost lanceolate, mostly entire ; rays very narrow, not 

 twice the length of the sparsely setose-hispid involucre. — Pcrs. syn. 2. p. 

 431 ,• Hook. fl. Bor.-Am. 2. p. 20. E. heterophyllum, MuU. ! in Willd. 

 spec. 3. ;j. 1956 ; Pers. I. c. ; Pursh ! fl. 2. p. 534 ; Nutt. ! gen. 2. p. 148 ; 

 Bart. veg. mat. med. t. 21 ; Darlingt. ! fl. Cest. p. 472. E. strigosum, 



* None of the North American species of DeCandoUe's Steiiactis accord with his 

 generic character, in which the simple pappus of the ray is said to be similar to the 

 inner pappus of the disk ; and it is equally at variance with the character given by 

 Nees. The two Asiatic species belong to Stenactis, of Nees. 



