Verbesina. — Helianthus. 995 
base obtuse. Achenes compressed with winged margins; pappus of 
2 aristae. — Herbs more or less hoary with opposite and alternate 
leaves and rather large loosely cymose pedunculate heads. — Xime- 
nesia Cay. 
A large American genus, with one species widely spread in the Tropics. 
1371. Verbesina encelioides (Cav.) Benth. and Hook. Gen. 
Plant. IT (1873), p. 380. — Aschers.-Schweinf. Ill. Flor. d’Eg., p. 89 
no. 549. — Pallasia serratifolia Sm. in Recs. Cycl. XXVI. — Xime- 
nesia encelioides Cay. Icon. II, tab. 178. — More or less hoary 
branched annual, 30—90 cm high. Stem and branches pubescent- 
tomentose, striate. Leaves mostly alternate at least the upper ones, 
from deltoid to oblong, dentate, broad near the sometimes excavated 
base, green and strigulose above, hoary with whitish closely ap- 
pressed tomentum below, 2'/,—9 by 2—6 cm exclusive of the 
winged auriculate petiole of 4—5 cm. Capitula 1—2?/, cm diameter, 
on peduncles ranging up to 10 cm. Outer bracts of the involucre 
linear acute herbaceous, about 1 cm long. Receptacle convex. 
Achenes pilose. — Flow. March to April. 
M. ma. M. p. N.d. N.f. N. v. D. a. sept. Cultivated in the 
gardens and often subspontaneous. 
A variable widely spread species originally from Mexico. 
572. (32.) Helianthus Linn. 
Annual or perennial caulescent herbs. Leaves alternate or 
opposite; blades simple, entire or toothed. Heads conspicuous. In- 
volucres flat, hemispheric; or cylindric; involucral-scales in several 
series, fleshy or leathery. Receptacle flat, convex or conic, chaffy. 
Ray-flowers neutral, ligules yellow. Disk-flowers bisexual, fruit- 
producing; corollas brownish or purple. Stigmas with pubescent 
appendages. Achenes flattened or somewhat or somewhat 4-angled. 
Pappus of 2 awns or scales, and these sometimes accompanied by 
2—4 shorter ones, all early deciduous. The plants flower in summer 
and fall, unless otherwise stated. 
A large genus widely distributed in America. 
A. Plants annual; receptacle flat or nearly so. 
I. Stem branched at the base the branches weak, 
diffusely spreading or decumbent .... . 1. H. debilis. 
II. Stem rigid and essentially erect. 
a) Foliage pubescent with silky wool, some- 
times floccose inage. .... . . . &. H. argophyllus. 
b) Foliage hispid, hirsute or eubuats «.).' 3. H. annuus. 
B. Plants perennial; receptacle convex or low-conie 4. H. tuberosus. 
63* 
