538 COMPOSITAE (COMPOSITE FAMILY) 



1. Nacrea lanata A. Nels. Bull. Torr. Bot. Club 26: 357. 1899. Stems 

 single, very strict, leafy, 2-4 dm. high: leaves (like the stem) densely white 

 lanate, thick, rather rigid, erect or somewhat appressed to the stem, sessile or 

 clasping, all nearly similar, narrowly oblong, the rounded-tapering apex sub- 

 acute, 4-8 cm. long, the floral much reduced: heads about 6 mm. high, bracts 

 wanting except for a few foliar ones at the lower pedicels; involucral bracts 

 ovate to narrowly obovate, the inner ones with a narrowed base : corolla-tube 

 slender, the limb slightly expanded, yellow: pappus-bristles barbellulate, the 

 unicellular barbules becoming large and obtuse toward the thickened apex 

 of the bristle; achenes roughened with upwardly pointed papillae. Known as 

 yet only from Goose Creek Canon, northern Wyoming. 



35. GNAPHALIUM L. CUDWEED. EVERLASTING 



Floccose-woolly herbs with sessile and sometimes decurrent leaves and 

 commonly numerous heads of small flowers in cymose clusters or glomerules. 

 Heads heterogamous, discoid, fertile throughout, of few or many series of 

 pistillate flowers surrounding a smaller number of hermaphrodite ones. In- 

 volucre pluriserial, imbricated, the scarious and commonly partly woolly 

 bracts with or without colored papery tips or appendages. Style of her- 

 maphrodite flowers 2-cleft. Pappus of numerous merely scabrous capillary 

 bristles in a single series. Achenes terete or flattish, mostly nearly nerveless. 



Heads not leafy-bracted; involucre woolly only at base; achenes glabrous. 

 Leaves tomentose on both faces. 



Narrowed at the base and not at all decurrent . . 1. G. Wrightii. 



Narrowed at the base and more or less decurrent . . . 2. G. chilense. 

 Leaves green on the upper face and glandular-viscid . . . 3. G. decurrens. 

 Heads leafy-bracted; involucres more involved in wool. 

 Freely and divaricately branched from the base. 



Tomentum dense and flpccose; leaves oblong to spatulate . 4. G. palustre. 

 Tomentum sparse (especially on the leaves) and appressed ; leaves 



all linear . . . . . . . . . 5. G. angustifolium. 



Simple and erect or with a few erect basal branches . . . 6. G. strictum. 



1. Gnaphalium Wrightii Gray, PL Wright. 1: 124. 1850. Low, 1-2 dm. 

 high, branched from the base, v the stems more or less branched throughout 

 or simple to near the summit ; stems and leaves grayish-woolly : radical leaves 

 oblanceolate, about 35 mm. long; the cauline, narrowly oblanceolate to linear, 

 1-3 cm. long: heads sessile in small glomerules terminating the branches; in- 

 volucres 4-5 mm. high; bracts dull white, from ovate in the outer to linear 

 in the inner, obtuse or acutish, nearly all apiculate. (G. sulphurescens Rydb. 

 Mem. N. Y. Bot. Gard. 1: 415. 1900; G. thermale E. Nels. Bot. Gaz. 30: 121. 

 1900, the description of which is here used.) Colorado to Texas and New 

 Mexico and on the Hot Springs formations, Yellowstone Park. 



2. Gnaphalium chilense Spreng. Syst. 3: 480. 1826. Stems usually stout, 

 2-7 dm. high: leaves lanceolate or linear, or the lowest spatulate, densely 

 white-woolly or sometimes thinly floccose, the short decurrent bases or ad- 

 nate auricles rather broad, slightly if at all glandular or heavy-scented : heads 

 in single or few close glomerules terminating the stem or branches; involucre 

 hemispherical, white or yellowish, becoming rusty-tinged. G. Sprengelii. 

 Texas to southern California and to Montana and Oregon. 



3. Gnaphalium decurrens Ives, Am. Journ. Sci. 1: 380. pi. 1. 1819. Stem 

 stout, 5-8 dm. high, corymbosely branched above and bearing cymosely 

 crowded glomerules of broad heads: leaves very numerous, lanceolate or the 

 upper linear, obviously adnate-decurrent, the upper face becoming naked and 

 green in age and with the stem glandular-pubescent or viscid, white-woolly 

 beneath, strongly balsamic-scented: involucre campanulate, white, becoming 

 rusty-tinged. From Texas and New Mexico to Washington and British 

 Columbia, and eastward to New England. 



4. Gnaphalium palustre Nutt. Trans. Am. Phil. Soc. 7: 403. 1841. Loosely 

 floccose with long wool; stems erect or diffusely branching from the base, 

 5-15 cm. high: leaves spatulate to oblong or lanceolate-linear, 15-20 mm. 



