Dipteronia OLIV.

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 : 58

Genus Dipteronia OLIV.

Text-fig. 9a

M a t e r i a l. USNM PAL 625742.

L o c a l i t y. Spring.

D e s c r i p t i o n. Samara 15.0 mm tall, 10.5 mm wide; pedicel 4.4 mm long, 0.4 mm wide; disc 0.5 mm tall, 1.7 mm wide; abortive fruit 1.1 mm in diameter; laminated vascular bundle emerging out of disc and into flat, circular seed body 1.0 mm in diameter, surrounded by circular wing 5.2 mm in diameter; veins radiate from center, dichotomizing occasionally between margin or halfway between margin and seed body; fimbrial vein surrounds wing.

R e m a r k s. The presence of a hypogynous perianth and disc scar at the junction of the pedicel and fruit and shape of the samara conform to Dipteronia . Fimbrial veins may be absent in Dipteronia fruit such as Dipteronia sinensis OLIV. or present such as in Dipteronia dyeriana HENRY and Dipteronia brownii MCCLAIN et MANCHESTER ( McClain and Manchester 2001). Dipteronia fruits are known from the Paleocene of Wyoming, the middle and late Eocene of British Columbia, Washington, Oregon and Colorado and the early Oligocene of Oregon ( McClain and Manchester 2001), as well as from the early Oligocene of western China ( Ding et al. 2018).

Figures

Text-fig. 9. a: USNM PAL 625742 Dipteronia samara showing pedicel, disc, an undeveloped fruit and a developed fruit. Scale bar 5mm. b: USNM PAL 621805 wings of cf. Boniodendron capsule. Scale bar 2mm. c: USNM PAL 625792 Sapindaceae capsular fruit with wings, septae and seeds. Scale bar 5mm. d: USNM PAL 623735 cf. Cedrela seed. Scale bar 3mm. e: USNM PAL 622276 Ailanthus confucii fruit showing seed body, ventral vein and stylar vein. Scale bar 5mm. f: USNM PAL 624113 Rutaspermum sp. Scale bar 2mm.