ROBINSON AND GREENMAN. — GENUS ZALUZANIA. 531 



ber in herb. Gray. Notwithstanding the general similarity subsisting 

 between this species and the preceding, the difference in the size and 

 form of the ultimate leaf-segments is sufficiently marked to warrant at 

 least varietal distinction, and in the absence of any evidence of inter- 

 gradation it seems best to maintain the species as proposed by Schultz. 

 SchafFuer's no. 345 from San Luis Potosi appears to be a glabrescent 

 form of this species. 



3. Z. anthemidifolia. Nearly glabrous except on the younger 

 parts : stems decumbent : radical leaves unknown, the cauline numerous 

 (12 to 22, the lower successively caducous), ovate and acute in general 

 contoui', 2-3-pinnate; ultimate segments obtuse or obtusish : peduncles 

 2 to 5 cm. long (shorter than in the related species) ; involucral scales 

 puberulent, obtuse or obtusish. — Wet sandy river banks, Guadalajara, 

 Jalisco, Pringle, 23 September, 1891, no. 5156. Type in herb. Gray. 

 With heads and habit of Z. globosa, but a smooth stem and numerous 

 cauline leaves of quite different contour and lobing. 



Subg. 2. Ferdinanda. Plants of drier habitat: disk 7 to 12 mm. in 

 diameter: rays 5 to 12 or none. — Ferdinanda., Lag. Elench. 31. 



* Rays present. 



■I- Leaves sinuate-lobed. 



++ Annual or biennial, usually pale with copious canescent or sordid pubescence : 

 rays about 8, short, 6 to 8 mm. in length. 



4. Z. TRILOBA, Pers. Stems 3 to 7 dm. high, branched above, canes- 

 cent-tomentulose to hirsutulous or granular : leaves sinuately bipinnatifid 

 with angular segments : heads rather numerous in terminal corymbs. — 

 Syn. ii. 473; DC. Prodr. v. 553; Hemsl. 1. c. ii. 160, iv. 55; Wats. 

 Proc. Am. Acad, xviii. 105. Z. trilohata, Hoffmgg. Verz. Pfl. Nachtr. 

 ii. 231, ace. to Hook. f. & Jacks. Ind. Kew. ii. 1245. Anthemis sinu- 

 ata, Llav. & Lex. Nov. Veg. Descr. i. 30. A. triloba, Ort. Dec. 72. 

 — A distinct and readily recognized species, apparently common from 

 Coahuila, throughout Central Mexico to Orizaba. 



++ -M- Perennial, green and smoothish; rays about 10, 2 cm. or more in length. 



5. Z. Grayana. Suffruticose, 6 to 8 dm. high, from a branched 

 lignescent stock surmounting a thick woody root : leaves ovate, petiolate, 

 3-lobed ; lobes rather broad, unequally toothed : involucral scales linear, 

 acute, canescent-pubescent : ray-flowers styliferous and fertile, their 

 achenes provided with a short irregular deciduous scale-pappus. — Gym- 

 nolomia triloba, Gray, Proc. Am. Acad. xvii. 217, & Syn. Fl. i. pt. 2, 



