﻿ALNUS. BETULACEiE (AUCTOR E. REGEL). 181 



crassatas, maturitate ase invicem secedentes, nunquam deciduae, lignes- 

 eentes. Nueulae compressae, apterae v. ala membranacea cinctae, abortu 

 uniloculares, monospermae. — Arbores et frutices sylvestres et paludosi. 

 Folia autumno v. rarius serius decidua. Floratio vernalis, nunc foliorum 

 evolutione praecocior [ v. coaetanea, nunc amenta florifera foliis adultis 

 anni praeteriti fulta. 



Sectio i. Clethropsis Endl. gen. suppl, 4. p. 20. — Genus Clethropsis Spach 

 rev. Bet. in Ann. d. sc. nat. set. 2. vol. 15. p. 20. 



Floratio cofetanea. Flores masculi : squamis unifloris, perianthio 10-12- 

 phyllo ; phyllis inaequalibus squamaeformibus. — Amenta utriusque sexus e 

 gemttus aphyllis, perulis omnino orbata; mascula longissima, gracilia, in pa- 

 niculam terminalem aphyllam disposita; foeminea soiitaria v. racemosa. Nu- 

 culas ala coriacea v. pellucida cinctae. 



1. A. nepalensis (D. Don prodr. fi. nep. p. 58), foliis integerrimis v. minute 

 calloso-denticulatis, amentis foemineis in quavis axilla racemosis, nuculis ala 

 pellucida iis duplo angustiore cincta. $ ln Nepalia, in Emodo, in Sikkim 

 Himalaya, in Bengalia orientali. — Wall. pl. as. rar. vol. 2. p. 27. t. 131 ; 

 Endl. 1. c. p. 20; Regel monogr. p. 83. t. 16. fig. 4-6, t. 13. fi>. 40-43. Cle- 

 thropsis nepalensis Spach rev. I. c- p. 202. Betula Ieptophylla Wall. cat. n. 

 2799. Arbor 30-40-pedalis. Ramuli teretes, brunnei, lenticellis adspersi, ju- 

 niores pube ferruginea adspersi glabrive. Folia ovata v. ovato-oblonga, acuta 

 v. subacuminata, v. rarius subobtusa, basi rotundata v. cuneata, integerrima 

 v. vix conspicue repandula v. minute calloso denticulata, supra laste viridia 

 nitida glaberrima, subtus glaucescentia , resinoso-punctulata et ad nervos 

 ferrugineo-puberula, excluso petiolo 4-5 poll. longa, 1 J--3 poll. lata; petiolus 

 \-\ poll. longus, glaber. Amenta mascula subfiliformia, usque 4 poll. longa. 

 Amentorum foem. racemi saepe penduli.' Strobili ovati. Nuculas ovato-oblongae, 

 apice stylis 2 brevibus rectis coronalse, ala membranacea sursum latiore 

 cincta?; ala nuculam subasquans v. usque triplo angustior, membranacea. 

 2. A. nitiba (Endl. in gen. pl. Suppl. 4. part. 2. p. 20), foliis ssepissime plus 

 minus evidenter crenulatis, amentis femineis in quavis axilla solitariis v. 

 binis, nuculis ala coriacea cinctis. — In Emodo, in Cashmir, in montibus 

 Kunawer. — Regel monogr. p. 82. t. 14. fig. 23-30. Clethropsis nitida Spacn 

 rev. I. c. p. 202; Spach in Jacquem. voy. part. bot. p. 159. t. 159. Ramuli fusci, 

 Ienticellis raris adspersi, juniores puberuli, deinde glabri. Folia elliptica v. 

 ovata v. ovato-lanceolata, acuminata v. apicem versus sensim attenuato-acu- 

 minata, basi cuneata v. rotundata, laeie viridia, lucida, subtus minutissime 

 resinoso-punctulata et in nervorum axillis barbulata, margine sub lente 

 remote calloso-denticulata v. crenulata v. evidentius crenulata v. denticulata, 

 2J-6 poll. Ionga, l^vS-J poll. lata. Pedunculus sub lente brevissime pube- 

 rulus |-1 \ poll. longus. Amenta feminea subfiliformia, usque 5 poll. longa. 

 Strobili oblongo-cyli ndrici, adscendentes v. subnutantes. Nuculas oblongas, 

 stylis brevissimis 2 erectis coronatae, ala coriacea nucula suba?quilata v. an- 

 gustlore cincta;. 



Sectio ii. Alnaster Endl. I. c. p. 20. — Genus Alnaster Spach rev. Bet. in Ann. 

 d. Mus. sir. 2. vol. 15. p. 200. 



Floratio foliis praecocior. Arnenta foeminea e gemmis 1-3-phyllis prodeuntia. 

 Nuculae ala membranacea cinctae. — Amenta mascula e gemmis terminalibus 

 lateralibusve aphyllis solitaria v. bina; squamae triflorae; perigonium regulare, 

 4-phyllum. Amenta masc. hieme nuda, foem. hieme perulata. 



3. A. vihidis (DC. fl. fr. vol. 3. p. 304), foliis ovatis v. subcordatis acutis v. 

 obtusis, racemis strobilorum foliis 1-3 ad autumnum persistentibus praeditis. 

 3 In montibus Europce, jn omni Sibiria, in Mandshuria et Japonia, in Sa- 

 chalin et Kamtschatka et in Americabtfreali. — Endl. gen. pl. suppl. 4. p. 20, 

 Regel monogr. p. 76. t. 14. fig. 4-22. Betula ovata ^chrank baic. fl. vol. 1 

 p. 419. B. Alnobetula Ehrh. Beitr. vol. 2. p. 72. B. viridis Chaix ap. Vill. fl 

 delph. vol. 4. p. 789. B. alpina Bork. A. undulata Willd. spec. vol. 4. p. 33P. 



