24 PROCEEDINGS OF THE AMERICAN ACADEMY. 



with pale stipitate glands; iuvolucre 8 to 10 mm. long; inner scales 

 narrowly liirear, attenuate, glandular, bristly chiefly near the midrib, 

 scarcely at all woolly : achenes columnar, striate, reddish brown, 3 mm. 

 long; pappus slightly tawny. — Jalisco: near Guadalajara, gravelly 

 banks, Pringle, no. 5133 (hb. Gr.), hillsides, Pn»^/e, no. 2090 (hb. Gr.), 

 dry gravelly banks, Pringle, no. 4461 (hb. Gr.). Territory of 

 Tepic : between Dolores and Santa Gertrudis, Rose, no, 2044 (hb. U. S. 

 Nat. Mus.). State of Mexico : Sierra de Ajusco, alt. 2440 m., Pringle, 

 no. 7211 (hb. Gr.). 



Var. Ghiesbreghtii, n. var. Pedicels and involucral scales covered 

 with close wool (tawny in dried specimens) as well as stipitate glands : 

 habit, etc., of the typical form. — Chiapas: growing in the plains, cool 

 region, Ghieshreght, no. 573 (hb. Gr.). 



Doubtful Species. 



H. stuposum Fries. Leafy at base, the summit of the caudex 

 woolly; stem 1 to 1.2 dm. high, almost naked, branched, slightly scab- 

 rous : radical leaves densely rosulate, petiolate, lanceolate, repand- 

 dentate ; the cauline reduced : inflorescence thyrsoidal, clothed with white 

 floccose pubescence; involucre soft-viilous : achenes narrowed down- 

 ward; pappus white. — Vet. Acad. Forh, 185G. p. 14G, & Epicris. 

 Hierac. 148 ; Hemsl. Biol. Cent.-Ara. Bot. ii. 2G0. — Mexico : 

 Ehrenberg. 



H. FRiGiDUM, Wedd. Chloris, And. i. 225 (1855) ; Klatt in Engl. 

 Jahrb. viii. 52. — Klatt, 1. c, ascribes this South American spe- 

 cies to Guatemala, a report based upon Lehmann's no. 1526, which 

 is not now in the Klatt Herbarium. No specimen from north of 

 Panama has been seen by the writers, which corresponds with the 

 South American plant. 



IV. — SYNOPSIS OF THE MEXICAN AND CENTRAL 

 AMERICAN SPECIES OF ALNUS. 



By M. L. Fernald. 



Several Mexican and Central American Alders of very diverse 

 characters have been generally called A. acuminata and A. jorullensis. 

 This disposition of the forms has been most unsatisfactory, and the fol- 

 lowing synopsis is offered as a partial solution of the difliculties presented 

 by them. 



