BARTLETT. — NOTES ON MEXICAN ALDERS. 609 



V. NOTES ON MEXICAN AND CENTRAL AMERICAN 



ALDERS. 



By Harley Harris Bartlett. 



Alnus acuminata HBK. A. acuminata a genuina Regel, Monog. 

 89 (1861), A. jorullensis var. acuminata (HBK.) Ktze. Rev. Gen. ii. 

 638 (1891), not A. acuminata Mirb. Mdm. Mus. Par. xiv. 464, t. 22 

 (1827), not A. acuminata a genuina Hemsl. Biol. Cent.-Arn. Bot. iii. 

 165 (1883), not A. acuminata Sarg. Silva ix. 79, t. 457 (1896), not A 

 jorullensis var. -q acuminata Winkl. Pflanzenreich, iv. 61, 127 (1904), 

 not A. acuminata Fern. Proc. Am. Acad. xl. 25 (1904). Here are 

 placed Seemann, no. 942, Loja, Ecuador, and, with considerable doubt, 

 Tonduz, no. 11,680, " Bords des rivieres au Copey," Costa Rica. The 

 latter specimen is much more ferrugineous than the former and forms 

 a transition to what has been called 



Alnus acuminata var. ferruginea (HBK.) Regel. ?? Alnus ferru- 

 ginea HBK. A. ferruginea Fern. Proc. Am. Acad. xl. 27 (1904) pro 

 parte. This name may be provisionally accepted for Tuerckheim, 

 no. 351, Coban, Department of Alta Verapaz, Guatemala, which seems 

 to be a very ferrugineous extreme of the plant here called A. acuminata. 

 The pubescence is very dense, and is persistent on all but the oldest 

 leaves. 



Alnus arguta (Schlecht.) Spach. Betula arguta Schlecht. Alnus 

 arguta Spach a genuina Regel, Monog. 93 (1861). In its typical 

 form this species is accepted as interpreted by Professor Fernald. It 

 presents, however, two variations which seem worthy of recognition. 

 Neither of them appears to fall into any of Regel's four varieties. His 

 var. genuina is here taken up as the type form of the species. Var. 

 Benthami is so inadequately characterized as to be unrecognizable with- 

 out access to the type. Moreover it came from Zacualtipan, to the 

 north of the known range of either of the two varieties here proposed. 

 Var. ovata was based upon material from three Mexican localities, 

 and one Peruvian locality, but since Regel cited as a synonym A. Mir- 

 belli var. Grisb. in Lechl. PI. Peruv. the type is definitely fixed as the 

 Peruvian element, which it is almost inconceivable should be the same 

 as the Mexican. Var. punctata was purely South American. 

 VOL. xliv. — 39 



