BETULACEAE. — ALNUS 503 



Subgen. III. ALNASTER EndJicher, Gen. Suppl. II. 28 (1842); IV. pt. 2, 20 

 (1847). — Regel in Bull. Soc. Nat. Mosc. XXXVIII. pt. 2, 421 (1865). — Pranti 

 in Engler & Pranti, Nat. Pflanzenfam. 111. abt. 1, 45 (1887). — Matsumura in 

 Jour. Coll. Sci. Tokyo, XVI. art. 5, 1 (1902. 



Alnus, sect. Alnohetida W. D. Koch, Syn. Fl. Germ. Helv. 603 (sine descrip- 

 tione) (1837); ed. 2, 762 (1843). — Winkler in Engler, Fjlanzenr. 1V.-61, 102 

 (1904). — Ascherson & Graebner, Syn. Mitteleur. Fl. IV. 413 (1911). 



Alnaster Spach in Ann. Set. Nal. s(5r. 2, XV. 200 (1841). — Ledebour, Fl. 

 Ross. III. pt. 2, 655 (1850). 



Almis, subgen. Alnibetida Petermann, Deutsche Fl. 516 (1849). 



Alnobelula Schur in Verh. Siebenbiirg. Ver. Naturw. IV. 68 (1853); Enum. PI. 

 Transsilv. 614 (1866). 



Alnus, sect. Alnaster Regel in Nouv. Mem. Soc. Nat. Mosc. XIII. pt. 2, 133 

 {Monog. Betulac. 75) (1861), exclud. A. napalensis et A. nilida; in De 

 Candolle, Prodr. XVI. pt. 2, 181 (1868). 



Alnus, subgen. Alnohetida K. Koch, Dendr. II. pt. 1, 625 (1872). — Dippel, 

 Ilandb. Laubhohk. II. 143 (1892). — Koehne, Deutsche Dendr. 112 (1893).— 

 Callier apud Schneider, III. Handb. Laubhohk. I. 120 (1904). 



Wolpert in Flora, C 37 {Vergleich. Anat. u. Entwicklungsgeschichte v. A. alno- 

 betula u. Betida) (1910) gives a very interesting account of the differences between 

 the true Alnus and the subgen. Alnaster and of the affinities of the latter with Betida. 



Series a. Virides Schneider, n. ser. (descriptio in clavi). 



The species placed into this group are very closely related. I doubt whether 

 the characters taken by Callier from the male flowers are constant enough to dis- 

 tinguish Alnus viridis^ Lamarck & De Candolle from A. sinuata Rydberg, etc. 

 The typical A. viridis does not occur within our area so far as I know, but Callier 

 (apud Schneider, III. Handb. Laubhohk. I. 121 (1904) refers specimens collected 

 by Middendorff " ad fl. Boganida " and others to var. typica, f. repens Callier, 1. c. 

 1 have not seen these plants, but they are referred to A. fruticosa by Trautvetter. 



13. Alnus fruticosa Ruprecht in Beitr. Pflanzenk. Russ. Reich, II. 53 {Fl. 

 Samojed. Cisural.) (1845). — Trautvetter in Middendoi-ff, Sibir. Reise, I. pt. 2, 

 Bot. abt. 1, 152 {Fl. Boganid.) (1857). — Komarov in Act. Hort. Petrop. XXII, 

 58 {FL Matish. II) (1903). — Callier apud Schneider, lU. Handb. Laubhohk. I. 

 121, fig. 66 h (1904); II. 888 (1912); in Fedde, Rep. Spec. Nov. X. 226 (1911). — 

 Koidzmni in Tokyo Bot. Mag. XXVII. 144 (1913). — Rehder in Bailey, -Stand. 

 Cycl. Hort. 1. 253 (1914). — Nakai in Tokyo Bot. Mag. XXIX. 45 (1915). 



Alnaster fruticosus Ledebour, Fl. Ross. III. pt. 2, 655 (1850). — Traut- 

 vetter & Meyer in Middendorff, Sibir. Reise, I. pt. 2, Bot. abt. 2, 85 {Fl. 



' There is some confusion about the sjTionj-ms of this species, which are given 

 as follows: 



Alnus viridis Lamarck & De Candolle, Fl. Frang. III. 304 (1805). 



Betula viridis Chaix apud Villars, Hi.<it. PI. Dauph. I. 374 (1786). 



Betula alnobetula Ehrhart, Beitr. II. 72 (1788). " 



Betula ovala Schrank, Baler. Fl. I. 419 (1789). 



Alnus ovata Loddigcs, Bot. Cab. XII. t. 1141 (1826). 



Alnaster viridis Spach in Ann. Sci. Nat. ser. 2, XV. 201 (1841). 



Alnus alnobetula Th. Hartig, Naturg. ForsU. Culturpfl. 372 (pro synon.) (1851). — 



SchweLnfurth apud Ascherson, Fl. Prov. Brandenb. 622 (1864). 

 Alnobetula viridis Schur in Verh. Siebenbiirg. Ver. Nalurw. IV. 68 (1853). 



