COMPOSITE. (COMPOSITE FAMILY.) 251 



55. GYMNOLOMIA, HBK. 



Scales of the involucre in two rows, the outer leafy, spreading, the inner 

 shorter, and similar to the rigid lanceolate cuspidate chaff of the conical 

 receptacle. Achenia short, striate. Pappus none. Otherwise like Kud- 

 beckia, with the habit of Helianthus. 



1. G. Porteri, Gray. Annual, rough witli short scattered hairs; stem 

 paniculately branched ; leaves lanceolate, entire, narrowed at each end, 

 fringed at the bai<e ; exterior scales of the involucre linear, as long as the 

 yellow disk ; rays 7-9, longer than the disk ; achenia biconvex, pubescent. — 

 Stone Mountain, Georgia. — Stem 2° -3° high. 



56. HELIANTHUS, L. Sunflower. 



Heads many-flowered ; the ray tiowers neutral ; those of the disk tubular 

 and perfect. Scales of the involucre imbricated in three or more rows, with 

 or without leafy spreading tips. Receptacle flat or convex, chaffy. Achenia 

 4-angled, usually compressed. Pappus of 2 (rarely 3-4) caducous chaffy 

 scales or awns. — Annual or perennial herbs, with opposite or alternate, com- 

 monly 3-ribbed, undivided leaves. Heads solitary, terminating the stem or 

 branches. Disk yellow or dark purple. Rays yellow. 



* Annual: disk dark purple: chaff of the receptacle ^-toothed: leaves on long 

 and slender petioles : achenia pubescent. 



1. H. Ploridanus, Gray (in part). Annual; stem. smooth, branching, 

 40 _ go higii ; leaves broadly lanceolate, denticulate, scabrous, the lower oppo- 

 site ; scale.s of the involucre lanceolate, smooth or ciliate ; rays 10- 13 ; chaff 

 of the receptacle entire ; achenia rugulose. — Dry old fields, East Florida. 



2. H. debilis, Nutt. Rough with scattered rigid hairs, villous when 

 young ; stem erect or decumbent, branched, somewhat spotted ; leaves 

 coarsely serrate, acuminate, undulate, the lowest deltoid-ovate, cordate, oppo- 

 site, the upper ovate-lanceolate ; scales of the involucre lanceolate-subulate ; 

 rays 1.5-20. — Sandy shores, Florida, and westward. July- Sept. — Stem 

 10-3° high. 



* * Perennial: disk dark purple. 



-4- Rays minute or wanting. 



3. H. Radula, Torr. & Gray. Stem simple, ascending, leafy and hirsute 

 towards the base, naked and smoothish above ; leaves thick, entire, rugose, 

 hirsute, the 4 radical ones large, roundish or rhombic; spreading; the lower 

 ones obovate, opposite ; the uppermost small, linear ; scales of the involucre 

 ()]>long-ovate ; rays mostly wanting ; chaff of the receptacle acuminate. — 

 Low sandy -pine barrens, Georgia, Florida, and Alabama. Oct. — Stem 2° 

 higli. Heads rather large. 



-t- -I- Raijs conspicuous. 



4. H. angustifolius, L. Stem rough-hairy or smoothish, simple, or 

 paniculately branched ; leaves linear, elongated, entire; with the margins 

 revolute ; the lowest ones opposite ; scales of the involucre lanceolate, acumi- 

 nate ; chaff of the receptacle 3-t()othed ; rays 12-18, showy. -^ Low ground, 

 common. Oct. — Stem 2° -6° high. Leaves 3' -6' long. 



