274 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. 



altitude 800 m., 25 December, 1906, C. Conzatti, no. 1653 (hb. 

 Field Mus. Catalogue no. 195851 ; fragment in hb. De Candolle). 



I am indebted to Dr. Casimir De Candolle for a detailed com- 

 parison of Professor Conzatti's plant with the type of Dysodia 

 serratifolia DC. From this species, as pointed out by Dr. De 

 Candolle, D. oaxacana differs in having smaller leaves, few heads 

 instead of a multiflorous corymb, and pubescent-tipped invo- 

 lucral bracts. 



To this natural group also belong D. integrifolia Gray, and 

 D. Seleri Rob. & Greenm. From the former the species described 

 above is readily separated by the pubescent branchlets and 

 puberulent leaves ; and from the latter by the presence of pellucid 

 glands on leaves and involucre. 



CHRYSACTINIA MEXICANA Gray, PI. Fendl. 93 (1849). Pectis taxi- 

 folia Greene. Leaflets Bot. Obs. & Crit. i. 148 (1905). 



Specimens collected at Kingston, New Mexico, by Mr. O. B. 

 Metcalfe, and distributed under no. 1440 (hb. Field Mus.), as 

 "Pectis taxifolia, Greene, n. sp." are identical with the above 

 species of Chrysactinia. 



LIABUM CADUCIFOLIUM Rob. & Bart. Proc. Am. Acad. xliii. 59- 

 (1907). 



To this very distinct species must be referred specimens 

 collected at Paso del Rio, State of Colima, Mexico, November, 

 1906, Dr. G. M. Emrick, no. 187 (hb. Field Mus.). Dr. Emrick's- 

 specimens show the uppermost leaves to be ovate, acuminate, 

 acute, entire or remotely mucronate-denticulate and abruptly 

 narrowed below the middle to an acute base. The mature 

 achenes, moreover, are 4 mm. in length, pubescent and strongly 

 striate. 



Schistocarpha platyphylla Greenman, sp. nov. 



Stem terete, striate, glabrous or slightly pubescent above: 

 leaves opposite, petiolate, ovate, 10 to 25 cm. long, 6.5 to 22 cm. 

 broad, acuminate, acute, sinuate-dentate, subcordate to cuneate 

 at the base and decurrent on the subconnate petioles, 3-nerved, 

 sparingly pilose on both surfaces, slightly paler beneath, thin 

 and membranous: inflorescence a terminal subcorymbose many- 

 headed pubescent panicle; bracts linear, subsetaceous : heads 

 7 to 8 mm. high: involucre narrowly campanulate; bracts of 

 the involucre 3-seriate, lance-oblong, 3 to 5 mm. long, i to 1.5 mm. 

 broad, obtuse or obtusish, pale stramineous, striate, glabrous: 

 pales hyaline, subcuneate, about 3 mm. long, irregularly 3-5- 

 toothed: pistillate flowers usually 13; corollas tubular; tube 

 2 mm. long, externally pubescent: perfect flowers 14 to 18;. 

 corollas about 5 mm. long, slightly exceeding the pappus; tube 

 puberulent, gradually ampliated above into a 5 -toothed limb: 

 mature achenes i mm. long, glabrous or sparingly puberulent 

 under a strong lens. GUATEMALA. Department of Quezal- 

 tenango: Santa Maria, 5 February, 1906, W. A. Kellerman, no. 



