20 PROCEEDINGS OF THE AMERICAN ACADEMY. 
aculeate or uncinate.— Benth. & Hook. f. acc. to Klatt, Leopoldina, 
xxiii. 2, where first described. — Mexico on the Rio Taba, Liebmann, 
no. 992. 
Doubtful species known chiefly or exclusively from cultivated specimens. 
Z. Reziu, Hort. Gard. Chron. 1872, page 1892; Hook. f. & 
Jackson, Ind. Kew. ii. 1251, is a mere horticultural name for a yellow- 
flowered annual species said to come from Mexico, but never properly 
described. 
Z. vertTiciLLaTA, Andrews, Bot. Rep. iii. t. 189, is apparently only 
a robust cultivated form of Z multiflora, with verticillate leaves, aud 
double series of rays: said also to come from S. Mexico. 
Z. HYBRIDA, Romer & Usteri, Mag. Bot. St. 1 (1787), 49; Curtis, 
Bot. Mag. t. 2123 (Z. grandiflora, Hort. fide DC. Prodr. v. 536, not 
Nutt.), is an annual with deep red rays, greenish disk, and chaff not 
fringed at the apex: apparently only a form of Z. multiflora, with rays 
becoming broad and somewhat double by cultivation. 
Z. ampicua, Salm-Dyck, and Z. piscoLor, Hort., are names only, 
and wholly obscure. 
IV.— REVISION OF THE MEXICAN AND CENTRAL 
AMERICAN SPECIES OF THE GENUS CALEA. 
CALEA, L., R. Br. (Name of obscure origin. The derivation 
from xadds, beautiful, is unsatisfactory, and at best very doubtful.) — 
Heads mostly small or of medium size, radiate or discoid. Tovaien 
ovoid, cylindrical, or campanulate; its scales pluriseriate, imbricated, 
usually very unequal, the outer gradually shorter, all scarious of the 
outer (rarely all) herbaceous or herbaceous-tipped. Receptacle small 
convex, or flattish, paleaceous : chaff scarious, concave, rigid or thin and 
hyaline. Ray-flowers when present fertile; ligules yellow, whity 7 
roseate, entire or denticulate at the apex. Disk-flowers fertile, yellow rae 
white; the limb of the corolla regular, deeply 5-cleft. Anthers appe®” 
daged at the apex and shortly sagittate-lobed at the base. Sty le-branches 
subtruncate or with a very short appendage. Achenes slender, subtereté 
or more or less distinctly 4-5-angled, usually pubescent: pappus - . : 
20 subequal scales; these mostly fringed or ciliolate, rarely wa? pe 
when numerous narrow and acuminate or when fewer usually short a0 
blunt. — About 85 species of shrubs and perennial herbs (rarely ei 
ers), extending from Mexico to Tropical S. America. Leaves opposite; 
simple, mostly ovate, oblong, or lanceolate, sessile or petiolate, mostly 
