Ailanthus confucii UNGER

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 : 58-59

Ailanthus confucii UNGER

Text-fig. 9e

M a t e r i a l. USNM PAL 622108, 622276, 622650.

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

D e s c r i p t i o n. Winged fruit elongate-elliptical, with a central seed body; wing with pointed apex and base; fruit 25.1–32.12 mm long, 7.3–8.6 mm wide; seed body 4.9–6.4 mm long, 3.7–5.3 mm wide; ventral (intramarginal) vein of the wing prominent, marginal or submarginal; stylar vein present, minor vein small, mostly parallel, occasionally dichotomizing or anastomosing (more on dorsal side); seed bodies sub-circular.

R e m a r k s. Ailanthus fruits in North America have traditionally been placed into either Ailanthus americana COCKERELL or Ailanthus lesquereuxi COCKERELL but are morphologically identical to those described earlier as Ailanthus confucii UNGER ( Corbett and Manchester 2004). The fossil matches the description of A. confucci by having a marginal to submarginal ventral vein as opposed to having an inset vein as in Ailanthus tardensis HABLY ( Corbett and Manchester 2004). A. confucii is recognized from the early Eocene through late Miocene of western North America ( Corbett and Manchester 2004). Among extant species, it resembles the temperate eastern Asian native species, Ailanthus altissima , which is invasive today in North America and Europe.

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.