326 COMPOSIT PSIL OCARPHUS 
| HESPEREVAX 
P. tenellus Nutt. 1. c. Canescently tomentose throughout with fine 
appressed wool which soon detaches from the stem: stems at length much 
depressed aud branched, 1-3 inches long: leaves spatulate, 3-6 lines long: 
heads very numerous, 2-3 lines in diameter: achenes half-line long, obo- 
vate-oblong. In low grounds, Washington to California. 
P. Oreganus Nutt. 1. c. Silky-lanate: stems erect, 2-6 inches high, 
‘branching from near the ground: leaves nearly linear, attenuate below, 4- 
‘6 lines long: heads numerous, 4-6 lines in diameter; achenes oblong-cylin- 
draceous. Low grounds and roadsides, Oregon and Washington. 
** Leaves little, and those subtending the heads seldom at all nar- 
rowed at base: herbage and especially the heads loosely floccose-woolly 
P. elatior Gray Syn. Fl. i, pt.2, Supp. 448. P. Oreganus var. elatior Gray. 
Erect and caulescent, or at length with spreading branches, 3-6 inches 
high, robust: leaves lanceolate or subspatulate-linear, 6-12 lines long: 
heads 4-6 lines broad, very leafy-subtended, loosely arachnoid-woolly, the 
the wool of the fructiferous bracts shorter and mostly close: achenes cylin- 
draceous. Low places, Willamette and Columbia river valleys. 
P. brevissimus Nutt. 1. c Stems very short, mostly simple: leaves ob- 
long or lanceolate, 2-5 lines long, seldom surpassing the leaves: heads sol- 
itary or very few, very woolly: achenes cylindrical or slightly clavate. 
“‘Plains of the Oregon’’ Nuttall, to California. | 
28 HESPEREVAX Gray Pac. R. Rep. iv 101, t. ii. 
Low annuals with mostly opposite leaves and small heads of 
inconspicuous flowers. Heads discoid, many-flowered ; the pis- 
tillate flowers with filiform corolla in several series on a conyex 
villous and centrally elevated columnar receptacle, each subtend- 
ed by an ovate barely eoncave chartaceous chaffy scale: herma- 
phrodite but sterile flowers several on the apex ofthe columnar 
receptacle, involucrate by a whorl of 8-7 coriaceous open bracts. 
Bracts of the involucre resembling the chaff of the receptacle. 
Pappus none. 
H. brevifolia Greene Fl. Fr. 102?. Evax caulescens Gray in part. Floc- 
cose-woolly: stems 4-12 lines high, simple,,or branching from the base, 
often depressed : leaves lanceolate, 4-6 lines long, tapering into a slender 
petiole: heads inconspicuous, in sessile terminal or axillary clusters, 
or solitary, a line or two long: chaffy scales of the receptacle, becoming 
rigid, those subtending the sterile flowers thicker and woolly inside: 
achenes oboyate-oblong with a narrowed base, straight, more or less com- 
pressed parallel to the subtending chatf, very smooth. Dry barren spots 
in prairies, southwestern Oregon and California. ‘ 
Subtribe ii Gnaphalex Less. Syn. 269. Heads discoid, heteroga- 
mous or androgynous or dieciously homogamous; the hermaphro- 
dite or staminat? flowers when in the same head much fewer than 
the pistillate ones; pistillate flowers with filiform tubular corolla 
shorter than the style; the staminate flowers with style or style-bran- 
ches mostly truncate. all usually with capillary pappus. Recepta- 
~ cle without bracts or chaff. Bracts of the involucre nwmerous, more 
or less scarious or with searious and often colored or petaloid swm. 
‘mits. Anthers with slender tatls. 
