322 planttE noy^ thurberianjE. 



Dysodia porophylloides (sp. nov.) : glabrum, e basi frutescente ramosissimum ; ra- 

 mulis striatis superne fere nudis monocephalis ; foliis parvis plerisque alternis bi - tri- 

 partitis, segmentis filiformi-subulatis mucronatis eglandulosis, superioribus in bracteas 

 subulatis minimis transeuntibus ; involucro turbinate 12-14-phyllo basi bracteis toti- 

 dem brevissimis subulatis integerrimis muticis cincto ; ligulis paucis involucrum et 

 pappum 10-paleaceum vix superantibus ; receptaculo fere nudo. — Sandy hills, near 

 San Felipe, between San Diego and the Colorado, California; May, 1852. — Branches 

 rigid, 1-^ to 2 feet high, from a frutescent base. Leaves (those of the flowering 

 branches alone seen) from nearly an inch to a quarter of an inch long, gradually re- 

 duced into bracts of one or two lines in length ; the larger with their divisions some 

 times 1 - 2-toothed, mucronate, but not setigerous. Involucre about half an inch long ; 

 the scales coalescent into a cup, linear, beset with oblong or linear glands ; their free 

 tips somewhat scarious, rather obtuse. The few and inconspicuous rays consist of a 

 linear ligule, the lower part of which is convolute around the style, while its expanded 

 apex very little surpasses the stigmas. Pappus 3 lines or more in length ; the palese 

 much like those of D. porophylla, but the undivided portion considerably longer. 



Psathyrotes incisa (sp. nov.) : arachnoideo-lanata ; caulibus humifusis dichotomis ; 

 foliis cuneato-oblongis argute inciso-lobatis, lobis dentibusve cuspidato-acuminatis ; pe- 



fallen. My kind friend Dr. Torrey having furnished me with some sketches and flowering heads, from 

 specimens subsequently gathered by Dr. J. M. Bigelow, while connected with the Mexican Boundary Cora- 

 mission, I have learned that the plant is not a Heterospermum, although allied to that genus, but it forms a 

 new generic type, the characters of which are briefly subjoined. 



DICRANOCARPUS, Nov. Gen. 



Capitulum pauciflorum ; floribus exterioribus 3-4 foemineis subradiatis, ligula minima 2-3-loba stylo bre- 

 viore ; disci totidem sterilibus, tubo corollas cylindrico, limbo cyathiformi 5-fido. Involucrum 1-2-bracteo- 

 latura (bracteolis linearibus parvis), 3-4-phyllum : squamas oblongas, obtusse, membranaceas, erectse, sub- 

 plante, deraum deciduse. Receptaculum planum : palese lineares parvse inter flores. Antheras oblongse, 

 ecaudatse. Stylus fl. masc. inclusus, indivisus, apice clavato pubescens ; fl. foem. bifidus, ramis inappendicu- 

 latis. Ovaria disci inania, epapposa. Achenia (radii) difformis, nempe 1-2 linearia vel subulata, subteretia, 

 IsBvia, persistentia, aristis 2 validis Issvissimis divergentibus seu recurvis persistentibus cornuta ; caetera brevi- 

 ora et crassiora, intus ssepe tuberculato-rugosa, aristis brevioribus vel obsoletis. — Herba annua, gracilis, fere 

 glabra, -He/erospermi facie, microcephala ; foliis oppositis 3-5-sectis, summisve integris, filiformlbus ; capi- 

 tulis solitariis pedunculatis ; floribus flavis. 



DicRANocAEPus PARViFLOEus. — Heterospermum dicranocarpum, Gray, PI. Wright. 1. p. 109. 



