Acer protonegundo

Name

Acer protonegundo

Rank

Species

Generic Name

[Genus] Acer

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

362

Year

1961

Parent Taxon

[Genus] Acer

Fossil Status

leaves (with fruits)

Stratigraphy

Miocene

Strat. comment

Yoshioka Formation

Location

Yoshioka, Fukushima-cho, Matsumae-gun, Hokkaido, Japan

Paleoregion

Eurasia (Japanese Archipelago)

Data for Holotypus

Repository

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

Repository Number

UHR-15004

Num

27: 2

Pub.

Neogene floral change in Japan [1961/3]

Data for Paratypus

Repository

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

Repository Number

UHR-15006

Num

27: 5

Descr.

Abura, Setana-machi, Setana-gun, Hokkaido, Japan; "Kunnui" Formation (Middle Miocene)

Pub.

Neogene floral change in Japan [1961/3]

Diagnosis

Leaves 3 foliate with medium-sized leaflets; leaflets elongate-ovate in shape, 3 to 10 cm long and 1.5 to 4.0 cm wide, cuneate or narrowly rounded at base, abruptly acute or pointed at apex; margin remotely and irregularly dentate, with pointed teeth; primary nerve slender, straight or eurving near the tip; secondary nerves 6 to 8 pairs, diverging from the midrib at the angles of 40 to 50 degrees, curving upwards, then, entering into the marginal teeth; craspedodrome; tertiaries thin, indistinct, forming an irregular mesh, near the margin branching to the sinuses;petioles stout and thick, 0.3 to 1.0 cm long; texture thin, membranaceous. Samaras elongate in shape, 3.6 to 3.8 cm long; wing slender, narrowly oblong, 2.5 to 2.8 cm long and 0.5 to 0,7 cm wide, outer margin nearly straight, inner margin gently curved, rounded at apex; veins numerous in number, curving inwards and diehotomously branching; seeds ellipsoidal in shape, 1.0 to 1.2 cm long and 0,4 to 0.6 em wide, buldged outside; angles between outer margin of wing and contact line of seeds about 20 degrees; contact line of seeds about 3 mm long.