TowNSENDiA. COMPOSITiE. 185 



29. TOWNSENDIA. HooTc. fl. Bor.-Am. % p. IG, t. 119. 



Heads subglobose, many-flowered ; the ray-flowers numerous in a single 

 series, pistillate, but sometimes infertile ; those of the disk tubular, perfect. 

 Scales of the involucre numerous and closely imbricated, appressed, lanceo- 

 late, with scarious margins. Receptacle flat, naked, areolate-fimbrillate. 

 Rays linear, often erect; the corolla of the disk infundibuliform, 5-tooihed. 

 Branches of the style lanceolate, rather acute, hairy towards the summit. 

 Achenia of the disk flat, obovate-oblong, pubescent or hairy, the margins 1- 

 nerved; those of the ray 3-nerved. Pappus of the disk-flowers composed of 

 numerous rather rigid and uniform barbellate-scabrous bristles, as long as the 

 corolla (slightly cohering at the base ? persistent) ; that of the ray of fewer 

 short subulate bristles or squamellse, sometimes with one or two slender bris- 

 tles intermixed. — Dwarf acaulescent or subcaulescenl herbs (natives of the 

 Rocky Mountains and the banks of the rivers which rise on their eastern 

 slope) ; with a branching caudex or a perpendicular root, and crowded linear 

 or spatulate entire leaves. Heads large for the size of the plant, sessile or 

 nearly so at the summit of the caudex, or of the proliferous branches. Rays 

 rose-color or nearly white. 



^ 1. Root perennial ; the caudex somewhat ligneous: rays fertile ; the short 

 pappus squamellate-suhulate, and mostly roith one or two capillary bristles 

 resembling those of the disk. — Townsendia proper. 



1. T. sencert (Hook.! I.e.): stemless ; leaves spatulate-linear, silky-ca- 

 nescent, erect, surrounding and partly concealing the sessile heads ; scales of 

 the involucre subulate-lanceolate ; rays long and narrow, with the margins 

 involute ; receptacle areolate ; achenia hairy ; pappus of the ray composed 

 of several unequal subulate bristles much shorter than theachenium, and one 

 or two long ones nearly resembling those of the disk-flowers. — Aster? exsca- 

 pus, Richards.! appx. Frank. journ. ed. 2. p. 32. 



/?. heads and flowers smaller; leaves narrower. — T. sericea, Nutt. ! in 

 trans. Amer.pihil. soc. {n. scr.) 7. p. 304. 



Carlton House on the Saskatchawan, Richardson! to the Rocky Moun- 

 tains in about lat. 54°, Drummond! (3. Black hills towards the sources of 

 the Platte in lat. 41°, Nuttall! April-May. — Root perpendicular, elon- 

 gated ; the caudex simple or divided, thick, very short ; the whole plant not 

 rising more than 2 inches in height. Leaves obscurely 1-nerved, 12-15 

 lineslong, mostly overtopping the sessile heads, which are ordinarily about 

 8 lines in length. Scales of the involucre pubescent, green in the centre (or 

 purplish towards the tip) ; the margins scarious and lacerate-ciliate. Rays 

 not spreading. Pappus of the disk white, longer than the corolla; the bris- 

 tles somewhat unequal, in alcjut 2 rows; the exterior thickened towards the 

 base, the interior more slender. Hairs of the acheniuna minutely capitate. — 

 The flower-bud, according to Dr. Richardson, is formed in the autumn and 

 expands the following spring. 



2. T. incawa (Nutt.) : caudex, or rather stems, branching ; leaves silky- 

 canescent, oblong-spatulate, tapering into a petiole, crowded, surrounding the 

 (small) sessile heads ; scales of ilie involucre oval-oblong, rather acute; rays 

 linear, flat; receptacle somewhat alveolate-limbrillate ; achenia minutely 



VOL. II. — 24 



