Betuloideae

Smith, MacKenzie A., Greenwalt, Dale E. & Manchester, Steven R., 2023, Diverse Fruits And Seeds Of The Mid-Eocene Kishenehn Formation, Northwestern Montana, Usa, And Their Implications For Biogeography, Fossil Imprint 79 (1), pp. 37-88 : 57

Betuloideae sp.

Text-fig. 8e

M a t e r i a l. USNM PAL 623160.

L o c a l i t y. Disbrow Creek.

D e s c r i p t i o n. Fruit a samara, circular in outline, 2.5 mm tall, 2.4–2.6 mm wide; seed body elliptical, in center of fruit, 2.1 mm tall, 1.6 mm wide; styles two, persistent, 0.4 mm tall and 0.1 mm wide with flat stigmas.

R e m a r k s. The specimen has a thin, differentiated wing as in most Betula species but has stout styles as in most Alnus species.

Figures

Text-fig. 8. Betulaceae and Juglandaceae from the Kishenehn Formation. a: DMNH L6933 Alnus sp. L1 leaves. Scale bar 2cm. b: DMNH EPI.48179 Alnus sp. leaf. Scale bar 2cm. c: DMNH EPI.48136b Alnus sp. leaf. Scale bar 2cm. d: USNM PAL 622756 Alnus sp. I1 infructescence attached to branch. Scale bar 1cm. e: USNM PAL 623160 Betuloideae showing wing, seed body and two persistent styles. Scale bar 1mm. f: USNM PAL 622732 Alnus sp. F1 samara showing two persistent styles. Scale bar 1mm. g: USNM PAL 624925 Betula sp. samara showing wing, seed body and two persistent styles. Scale bar 1mm. h: USNM PAL 623147 Alnus sp. F2 samara showing. Scale bar 1mm. i: USNM PAL 622690 Palaeocarya sp. samara showing three wings with reticulate venation and hairs at base. Scale bar 1cm.