Agrimonia sp.

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 : 55

Agrimonia sp.

Text-fig. 7f

M a t e r i a l. USNM PAL 620816, 621198.

L o c a l i t y. Park.

D e s c r i p t i o n. Pedicel 1.7 mm long, 0.4 mm wide at base and 0.9 mm wide at apex; achene 2.6–4.2 mm long, 1.6–3.8 mm wide; at least 7–16 apically extend linear bristles arising from apical portion of fruit; bristles 1.0– 1.8 mm long, 0.1–0.3 mm wide, apices acute or tapering distally with rounded apices, two filaments on USNM PAL 621198 0.6 mm long, 0.04 mm wide.

R e m a r k s. This fossil corresponds in size and morphology to fruits of Agrimonia with a wide calyx, wideribbing on the calyx and many persistent bristles ( Guo 1998). Whereas in some Agrimonia species the bristles are hooked in the fruit, they can be erect in others ( Kline and Sørensen 2020: fig. 7g). We also compared this fossil to petalless inflorescences of asteraceous taxa like Bidens L., Rhodanthemum B.H. WILCOX, K. BREMER et HUMPHRIES , and Leucanthemum SAMP. but those genera have individual bracts that surround the base of the inflorescence rather than an achene topped with bristles (pers. obs.). The Kishenehn specimen represents the first fossil record of the genus.

Figures

Text-fig. 7. a: USNM PAL 722490 cf. Myriophyllum fruit. Scale bar 1mm. b: USNM PAL 624027 three-valved Populus sp. capsule on pedicel. Scale bar 3mm. c: USNM PAL 717328 Deviacer wolfei samara. Scale bar 5mm. d: USNM PAL 621987 Fabaceae sp. 1 Legume fruit showing persistent style. Scale bar 2mm. e: USNM PAL 625803 Fabaceae sp. 2 fruit. Scale bar 5mm. f: USNM PAL 620816 Agrimonia sp. fruit. Scale bar 3mm. g: Modern Agrimonia pubescens fruit (image by Tracey Slotta, United States Department of Agriculture National Resource Conservation Service Plants Database). h: USNM PAL 621976 Ulmus sp. F1 fruit showing two persistent styles. Scale bar 2mm. i: DMNH EPI.48205 Ulmus sp. L1 leaf. Scale bar 1cm. j: UF 19652-86483 endocarp of Celtis sp. k: UF 19652-86484 Endocarps of Celtis sp.