BETULACEAE. — ALNUS 489 



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Arbor 7-26 m. alta; ramuli novelli dense fulvo-tomentosi, annotini 

 glabrescentes, purpureo-brunnei, lenticellis parvis obtecti; dein nigres- 

 centes; gemmae stipitatae, ovato-obtusae v. subglobosae, subglabrae, 

 resinosae, stipite tomentello. Folia obovato-oblonga v. clliptica, 

 basi acuta v. subrotunda, apice obtusaj sed pleraque in acuminem 

 brevem producta, margine (apice distinctius) satis aequaliter distanter 



+ 



brevi-glanduloso-serrata, supra saturate viridia, novella plus minusve 

 pilosa, adulta fere glabra, subtus initio dense fulvo-tomentosa, deinsaepe 

 facie glabrescentia, pallida viridescentia, costa nervisque prominulis 

 fulvo-tomentella v. hirsuta, costa interdum glabriuscula, nervis lateral- 

 ibus utrinque circiter 10-13, axillis barbata, 6-15 cm. longa et 4,5-10 

 em. lata; petioli initio densius tomentelli, dein sulco superno excepto 

 glabrescentes, crassi, 0.8-2 cm. longi. Amenta ut in descriptione 

 subgeneris (p. 490), mascula ad 6 cm. longa; pedunculi utriusque sexus 

 initio fulvo-tomentelli. Strobili maturi singuli, pedunculis 3.8-4.5 cm. 

 longis sufFulti, elliptici, utrinque obtusi, 2-2.6 cm. longi, 1-1.6 cm. 

 crassi; bracteae apice truncatae, utrinque indistincte brevi-lobatae 

 et breviter incisae, circiter 7 mm. longae et 8-9 mm. latae; semina 

 obovato-oblonga, basim versus subacuminata, alis distinctis mem- 

 branaceis nuculo sublatioribus, apicem versus vix dilatatis cincta, 

 circiter 5 mm. longa. 



Western Szech'uan: southeast of Tachien-lu, side of streams, 

 local, alt. 1600-2500 m., October 1908 (No. 1377, type of description; 

 tree 7-26 m. tall, girth 0.9-3 m.; with fruits); same locality, June 1908 

 (No. 1377^; with flowers); same locality, side of streams, alt. 1609- 

 2000 m., October 1908 (No. 1377°; tree 10-20 m. tall, girth 1.2-2.4 

 ni.; with fruits); same locality, woodlands, side of streams, alt. 1000- 

 2200 m,, October 1910 (No. 1377^; tree 26 m. tall, girth 3 m.; with 

 fruits); same locality, alt. 1600-2300 m. (June ?) 1904 (Veitch Exped. 

 No. 4498; tree 7-13 m. tall; with flowers and old fruits). 



This species is very closely related to A. cremasiogyne Burkill, but it is easily 

 distinguished from it by the character given in the key. There are young plants 

 growing in the Arnold Arboretum. For further remarks see the subgen. Crenia- 

 stogyne, p. 492. 



This tree is local in its distribution and is known to me only from a limited area 

 to the southeast of Tachien-lu, where it is common between 1600 and 2300 m. alti- 

 tude. In habit it is similar to A. cremastogyne Burkill, but the trunk is usually 

 thicker and the branches stouter. E. H. W. 



