COMPOSITAE 



47. HEMIZONIA 

 Viscid-glandular and ill-scented animals with alternate (or the lowest some- 

 times opposite) narrow Leaves. Flowers yellow or white, in mostly numerous 

 beads. Disk (lowers surrounded by a circle of chaffy and often slightly united 

 bracts or the disk chaffy throughout. Receptacle flat, its bracts deciduous. Ray- 

 achenes thick, short, turgid, half enclosed by the lower part of the bract of 

 the involucre which falls with it or is at least deciduous. Disk-achenes sterile, 

 with or without pappus. This and the two following genera were perhaps better 

 received as one. (Greek hemi, halt', and zonia, zone, the bracts but half 

 enclosing the fruit.) 



A. Ray-achenes not beaked. 

 Receptacle with chaffy bracts throughout; areola of ray-achenes nearly or quite central 

 at the summit of the achene; disk-achenes without pappus; flowers white, sometimes 

 yellow. 



Rays scarcely surpassing the bracts of the involucre 1. H. congesta. 



Rays showy, much surpassing the bracts of the involucre. 



I leads paniculate or corymbose 2. H. luculacfolia. 



Heads raccmosely disposed along simple branches 3. H. clevelandii. 



B. Ray-achenes beaked. 

 Receptacle with a circle of bracts surrounding disk-flowers, otherwise naked; leaves 

 without truncate glands; flowers yellow. 



Rays 12 to 25; pappus minute or none; heads hemispherical 4. H. corymbosa. 



Rays 5; pappus of linear paleae; heads very narrow. 



I I cads on slender pedicels 5. H. kelloggii. 



Heads fascicled in small clusters 6. H. fasciculata. 



Receptacle with chaffy bracts throughout; leaves of the branchlets with small truncate 

 glands at tip; pappus none. 



Rays 4 or 5 ; leaves crowded on the branchlets 7. H. virgata. 



Rays 5 to 8; leaves scattered on the branchlets 8. H. hecrmannii. 



1. H. congesta DC. Soft-hirsute or villous, the inflorescence slightly glan- 

 dular; lowest leaves commonly opposite, oblanceolate, sparsely serrulate, the 

 upper linear or linear-lanceolate and entire; heads terminating paniculate or 

 corymbose branches; bracts of the involucre with lanceolate foliaceous tips, 

 which are little surpassed by the rays; outer bracts of the receptacle either 

 lightly connate or nearly distinct; achenes with conspicuous inflexed stipe. 



First collected by Douglas "in Calif ornia, ' ' doubtless between Monterey and 

 Sonoma; attributed by Greene to Marin Co., etc. 



2. H. luzulaefolia DC. Hay-field Tarweeu. Whole plant excepting the 

 lowest leaves very glandular and ill-scented; stems erect, 1 to 2 ft. high, 

 corymbosely or paniculately branched at summit, or branching more freely and 

 dill use; lower leaves crowded and more or less tufted, narrowly linear, mostly 

 tapering somewhat to the apex, 3 to 5 in. long, 1 or 3-nerved, canescent with 

 appressed soft silky hairs which are more or less floccose-deciduous; upper 

 leaves much reduced; heads numerous, on short peduncles, which are nearly 

 naked or bear very much reduced leaves; tips of the involucral bracts acute 

 or obtuse; outer bracts of the receptacle united into a cup; rays 6 to 10, 

 white or pink-tinged; achenes with very short stipe. 



Abundant in mowed hay fields and pasture lands: Sacramento and San 

 Joaquin valleys and westward through the Coast Range hills and valleys to 

 the ocean. July-Oct. Var. lutescens Greene. Flowers yellow. — Fields near 

 San Francisco Bay, in Contra Costa, Napa, and Marin cos. Var. citrina 

 Jepson. Lowest leaves glandular-pubescent, without appressed woolly hairs; 



flowers lemon-yellow. — Northern Marin Co. Apr. -May. 



3. H. clevelandii Greene. General habit of the preceding, but the herbage 



much leSB glandular; involucres white hairy toward the base; heads disposed to 



In- racemose on the branches as well as terminal. 



