ROBINSON. — GALINSOGA. 325 



hirsute-pubescent upon both surfaces ; the central lobe lanceolate 

 attenuate to a sharp point, 3-uerved, l£-2£ inches long, 3-7 lines 

 broad; lateral lobes G-8 lines long, somewhat falcate, obtuse; the 

 uppermost leaves reduced, entire ; petioles j inch long : stamiuate 

 racemes slender, loosely flowered, including the peduncle 2-4 inches 

 long : pedicels j line long, equalling or somewhat exceeding the minute 

 subulate bractlets : perianth \\ lines broad; segments of two forms ; 

 the 3 outer spreading, oblong, obtuse ; the inner a little narrower and 

 acutish, ascending, incurved : stamens 3, very short, perhaps one third 

 as long as the segments of the perianth : fruiting raceme 1^-2 inches 

 long upon peduncles of nearly ecpjal length : capsules glabrous, re- 

 flexed, somewhat imbricated, elliptic in outline, 6 lines long, half as 

 broad. — Collected upon the steep sides of wet cliffs of the barranca 

 of Guadalajara, 8 September, 1893 (no. 5434). 



III. —NOTES UPON THE GENUS GALINSOGA. 



Few genera have been subject to so much doubt as to proper lim- 

 itation as Galinsoga. This is equally evident from its treatment in 

 I)e Candolle's Prodromus, in which of its supposed six species five 

 are questioned, and from the writings of subsequent authors who have 

 dealt with it. Satisfactory generic limitations can perhaps only be 

 obtained by a monograph including uot only the plants hitherto as- 

 cribed to Galinsoga, but several neighboring genera, for which suffi- 

 cient material could only be found in the larger foreign collections. 

 Something, however, may well be done at more accurate specific and 

 varietal definition of forms growing within our own country. So far 

 as I know, only one species is at present recognized upon the continent 

 of North America north of Mexico, that is G. parviflora, Cav. The 

 telling characteristics of this species, when obtained from the earliest 

 descriptions and figures as well as from the examination of material 

 completely in accord with these, are as follows : stem and branches 

 smoothish or finely and more or less appressed pubescent : rays white or 

 whitish, little exserted: pappus of the disk flowers consisting of spatulate 

 obtusish scales equalling the achene. Of this species several varieties 

 have been suggested. Dr. Gray in the PL Wrightiana, ii. 98, founded 

 two upon the relative development or absence of the pappus in the 

 ray flowers ; namely, var. semicalva, with naked ray achenes, and var. 

 Caracasana, with abortive ray pappus. The writer has examined a 

 large number of specimens of the spesies both from North America 

 and from the most widely separated regions of the world, and finds 



