Alnus arasensis

Name

Alnus arasensis

Rank

Species

Generic Name

[Genus] Alnus

Authors (Name)

Huzioka K.  

Authors (Pub.)

Tanai T.  

Publication

Neogene floral change in Japan [1961/3]

Journal

Journal of the Faculty of Science of the Hokkaido University

Volume

11

Issue

2

Page number

279

Year

1961

Fossil Status

leaves

Stratigraphy

Miocene

Location

Aburato coal mine, Kamo-machi, Tsuruoka City, Yamagata Prefecture, Japan

Paleoregion

Eurasia (Japanese Archipelago)

Data for Holotypus

Repository

National Museum of Nature and Science, Palaeobotany Collection, Tokyo, Japan

Repository Number

UHR-15144

Diagnosis

Leaves elliptic-oval to oval in general outline, 5.5 to 6.3 mm Iong and 3 to 3.5 cm wide ; apex acutely pointed, somewhat aeuminate; base obtuse or rounded, sometimes obliquely truncate, very slightly deeurrent at the very base; midrib rather slender, nearly straight; secondary nerves slender, 8 to 11 pairs, opposite at the lower part and subopposite at the upper, diverging from the midrib at angles of 40 degrees on the middle part of blade, less at the upper part, 2 or 3 basal pairs short, diverging from the midrib at nearly right angles, all secondaries nearly straight, gently cvrving up near the margin, then entering marginal teeth ; a few tertiaries branching from secondaries near the margin, and entering into teeth ; tertiaries among intersecondary spaces very thin, irregularly percurrent; nervilles very thin, forming fine polygonal meshes; margin serrulate, with fine and acute teeth; nearly equal-sized; texture firm, membranaceous; petiole slender, about 7 mm long.