JuLy 19, 1923 STANDLEY: TWO NEW GENERA OF RUBIACEAE 289 
Pseudoclappia arenaria Rydberg, sp. nov. 
Clappia suaedaefolia Woot. & Standl. Contr. U. 8. Nat. Herb. 19:719. 1915. 
Not C. suaedaefolia A. Gray. 1859. 
A low shrub; leaves linear, 1-3.5 cm. long, 1-2 mm. thick; peduncles 
2-4 em. long, with a few scalelike subulate small leaves; involucral bracts 
glabrous, linear, acute, 8-10 mm. long; ligules yellow, 6-8 mm. long, 2-2.5 
mm. wide; disk-corollas about 1 cm. long; achenes blackish, prismatic, 
3 mm. long, 1 mm. thick. 
New Mexico: White Sands, Otero County, July 20, 1901, Wooton (type; 
U. S. Nat. Herb. no. 739956); Aug. 31, 1904, Wooton 2618; June 21, 1895, 
Wooton. White Sands, Dona Ana County, July 19, 1897, Wooton 483. 
South Spring, May 2-4, 1908, Griffiths 4243 (U. 8. Nat. Herb. no. 496288, 
in part). 
The plant can not be included in Clappiza since it lacks the resinous stria- 
tion of the bracts and the fimbrillae on the receptacle, and the bristles of 
the pappus are neither flattened nor paleaceous at the base. It can not be 
included in Senecio since the involucre is without caliculum and its bracts 
of a different texture, the pappus-bristles are stiffer than is usual in that 
genus, and the style-branches are distinctly Vernonioid, neither truncate 
nor with a hair-pencil at the end. The genus should, however, be referred 
to the tribe Senecioneae, subtribe Senecionanae, notwithstanding the Ver- 
nonioid style. A more or less vernonioid style is found also in the genera 
Gynura, Emilia, and Psacalium. 
BOTANY.—Calderonia and Exandra, two new genera of the family 
Rubiaceae. By Pau C. Stanpiey, U. 8. Nationat Musevum.! 
During a botanical collecting trip to the Republic of Salvador in 
1921-22 the writer obtained imperfect material of two trees of the fami- 
ly Rubiaceae, both of which prove to represent undescribed genera. 
Both of them had been obtained by earlier collectors, and specimens 
existed in the National Herbarium, but the early material was too in- 
complete for satisfactory identification and has remained undetermined 
until now. 
Of the two genera here described the more interesting and better 
defined is Calderonia, of which a complete series of specimens, showing 
both flowers and fruit from the same tree, has been collected by Dr. 
Salvador Calder6n, of the Chemical Laboratories of the Salvadorean 
Department of Agriculture. Dr. Calder6nisan enthusiastic student of 
botany and entomology, and has presented to the National Museum 
an unusually interesting collection of Salvadorean plants, beautifully 
prepared and consisting of over 1500 specimens, which are of excep- 
tional value because of the vernacular names and full notes: upon 
economic applications which accompany them. 
1 Published by permission of the Secretary of the Smithsonian Institution. 
