72 PROCEEDINGS OP THE AMERICAN ACADEMY. 



form, 2 to 6 cm. long, with conspicuous subulate tips and 2 rows of dark 

 glands, entire or rarely with 1 or 2 small lobes, but no setae at the bases : 

 peduncles elongate, 1^ to 2 dm. long, with many bracts, the lower bracts 

 leaf-like, the upper reduced : heads large, 1 cm. or so high, almost as broad, 

 60-80-flowered ; involucre of 8 to 15 oblong bracts thickened and herba- 

 ceous below, with conspicuous dark glands, scarious above, with round or 

 subtruncate erose tips : rays oblong, 1 cm. long, white, becoming dark- 

 striped with age : pappus sordid, of 10 to 20 subequal linear-subulate 

 setiferous pales, a few of them setiform and hardly paleaceous below, 4^ 

 or 5 mm. long, equalling the glabrate akeues. — Proc. Am. Acad. xxv. 

 155. — CoAHUiLA, calcareous hills, Carneros Pass (Pringle, no. 2403). 

 Originally placed by Dr. Watson in § Pectothrix, but the definitely pale- 

 aceous pappus, strongly resembling that of P. Sinaloensis, places it rather 

 in this section. 



§ 2. Pectidopsis, Gray. Annuals, or rarely perennials (?) with nar- 

 row leaves setiferous at the bases : involucre short-cylindrical, the bracts 

 linear, often becoming strongly involute : pappus of a few (1 to 6) slender 

 upwardly scabrous setiform rather rigid awns sometimes dilated at the 

 bases, with or without a short crown of separate or united squamellcE, or 

 sometimes reduced merely to the crown. — PI. Wright, i. 82. Helioreos, 

 Raf. Atl. Jour. (1832) 145. Pectidopsis, DC. Prodr. v. 98. Pedis § Eu- 

 pectis, Gray, Proc. Am. Acad. xix. 44, in part. 



* Low branching herbs with elongate-linear leaves : heads subsessile or short- 

 peduncled, fastigiate : involucre about 8-bracteate. (Forms of P. papposu may 

 be looked for here.) 



P. tenella, DC. Low, 2 dm. or less high, spreading and branching 

 from near the base : stems angulate, smooth or minutely puberulous : 

 leaves mucronate, H to 4 cm. long, 1 or 2 mm. wide, broadened at the 

 bases, with prominent midribs and 2 rows of large glands on the lower 

 sides ; margins revolute, with 1 to 4 pairs of setae at the bases : involucre 

 4 or 5 mm. high, 15-25-flowered ; the bracts prominently keeled, with 

 scarious margins, bearing toward the tips a large gland, and sometimes 1 

 or 2 below : rays oblong, 3i to 5 mm. long, yellow : pappus merely of 2 

 to 6 slender variously unequal awns, the longest 2 to 4 mm. long: akenes 

 slightly lonuer than the pappus, smooth or minutely short-setulose. — 

 Prodr. V. 99 ; Gray in Torr. Bot. Mex. Bound. 73 & Proc. Amer. Acad. 

 xix. 46. Plains, Southern Texas to Chihuahua and Tamaulipas. 

 Texas, Laredo, and between the Rio Grande and the Nueces (Berlandier, 

 nos. 599, 985, 2009, 2415), Rio Coleto (Thurber, no. 19) ; Chihuahua, 

 Chihuahua (Pringle, no. 648) ; Tamaulipas, near Mier (Gregg, no. 62). 



