380 PROCEEDINGS OF THE AMERICAN ACADEMY. 
summis alternis denique minimis linearibus; capitulis paniculatis; 
disco 11-15 mm. alto 8-12 mm. diametro; involucri squamis 4-seriatis 
exterioribus sensim brevioribus striatis margine et apice minute 
glanduloso-strigosis lanceolatis interioribus lanceolato-attenuatis disco 
subaequalibus; radiis ca. 12 oblongo-ovalibus flavis 6.5 mm. longis; 
disci flosculis 8 mm. longis (tubulo 1.5 mm.) puberulo-glandulosis 
flavidis denique purpurascentibus; paleis 11.5 mm. longis lateraliter 
sublaceratis dorso et apice oe acuminato glanduloso- 
pubescentibus; acheniis 5 mm. longis 2.4 mm. latis appresse pubes- 
centibus interdum subglabris — scilintie calvis. vel cum aristis 2 
tenuibus sursum ciliatis ad 2.2 mm. longis. 
Specimens examined: Sonora: Mate 16-30 Sept. 1890, Palmer 
741 (corypes in Gray Herb. and Nat. Herb., no. 46131).— Distributed 
as Encelia mexicana, from which it is very distinct. 
++ ++ Leaves unlobed; stems merely glandular; heads 9-10 mm. high, 5-7 
mm. wide. 
3. S. tenuis (Fernald) Blake, n. comb. Base and lowest leaves 
unknown; stem finely and thickly glandular, only the ultimate 
branches of the inflorescence somewhat setose; leaves deltoid-ovate, 
cordate with broad shallow sinus, acute, crenate, glandular-puberu- 
lent and somewhat strigose, on glandular and setose barely margined 
petioles 1—-2.5 em. long, with their bases united into rounded crenate 
foliaceous disks; inflorescence much branched, the branches slender, 
the very slender peduncles 2-10 cm. long; heads short-cylindric; 
scales 3-4-seriate, distinctly graduated, the outer ovate, the inner 
lance-acuminate, glandular-puberulent, ciliate above, striate-veined; 
rays about 8, yellow, oval, 6 mm. long, barely bidentate, hairy on tube 
and sl bescent on back; disk-corollas 5.8 mm. long, glandular- 
ssiheebidies a n tethe and pubescent above, yellow becoming purplish; 
pales 7-8 mm. long, glandular-puberulent; achenes dark-mottled, 
appressed-pubescent, awnless, 5 mm. long, 3 mm. wide. 
Encelia tenuis Fernald, Proc. Am. Acad. xxxiii. 94 (1897). 
pecimens examined: GuERRERO; rather scarce on edge of a corn- 
field, Nov. 1894, Palmer 96 (FGN, TYPE COLLECTION). 
* * Petioles sometimes auriculate, not connate at base into disks; anruals or 
perennials. 
+ Rays yellow. 
++ Involucral scales distinctly unequal, the outer ovate, 3—4-seriate. 
= Achenes glabrous and awnless. 
x Petioles not auriculate. 
4. §. exaristata Gray. Annual, erect, much branched above, 
the stem and branches striate, covered with a fine glandular pubescence 
