Platanus

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 : 51

Genus Platanus L.

Text-fig. 6c–f

M a t e r i a l. USNM PAL 622299, 768140.

L o c a l i t i e s. Dakin and Disbrow Creek.

D e s c r i p t i o n. Achene obovate 8.8–8.9 mm long, 1.7 mm wide with flat base rounding to acute apex and elongate style 3.7–4.1 mm long and 0.2 mm wide, single seed obovate to fusiform preserved inside 3.3–5.1 mm long and 0.4–0.9 mm wide with thickened micropylar end, many dispersal hairs 0.5–1.8 mm long arise from base of achene directed apically.

R e m a r k s.The presence of dispersal hairs distinguishes Platanus fruits from the fruit of Macginicarpa (the fossil genus used for fruits associated with Macginitiea J.A. WOLFE et W. WEHR in Manchester leaves) (Manchester 1986, Huegele and Manchester 2022). Platanus fruits are known from the mid-Eocene Clarno Nut Beds of ( Manchester 1994). Platanus is an indicator for riparian environments ( Nixon and Poole 2003).

Figures

Text-fig. 6. a: USNM PAL 625188 cf. Ceratophyllum fruit. Scale bar 1mm. b: USNM PAL 722388 cf. Thalictrum sp. Scale bar 2mm. c: USNM PAL 622299 Platanus sp. achene with prominent seed body. Scale bar 2mm. d: USNM PAL 768140 Platanus sp. achene with dispersal hairs. Scale bar 2mm. e: Close-up of USNM PAL 768140 Platanus sp. achene with red arrows pointing to dispersal hairs. Scale bar 2mm. f: USNM PAL 622299 Platanus sp. achene with red arrows pointing to hairs. Scale bar 2mm. g: USNM PAL 623312 winged seed of Carpolithes lunatus. Scale bar 1mm. h: USNM PAL 625269 winged seed of Carpolithes lunatus. Scale bar 1mm. i: USNM PAL 625257 winged seed of Carpolithes lunatus with highly curved wing. Scale bar 1mm. j: USNM PAL 624499 winged seed of Carpolithes lunatus. Scale bar 1mm. k: USNM PAL 622294 winged seed of Carpolithes lunatus with raphe wrapping along wing towards the chalazal end of the seed body. Scale bar 1mm. l: USNM PAL 717434 winged seed of Carpolithes lunatus with raphe wrapping along wing towards the chalazal end of the seed body. Scale bar 1mm. m: USNM PAL 625251 winged seed of Carpolithes lunatus with raphe wrapping along wing towards the chalazal end of the seed body. Scale bar 1mm. n: USNM PAL 625541 elongated winged seed of Carpolithes lunatus with raphe wrapping along wing towards the chalazal end of the seed body. Scale bar 1mm. o: USNM PAL 625286 elongated winged seed of Carpolithes lunatus. Scale bar 1mm. p: USNM PAL 624179 winged seed of Carpolithes lunatus with raphe wrapping along wing towards the chalazal end of the seed body. Scale bar 1mm. q: USNM PAL 620034 cf. Jenkinsella knowltonii. Scale bar 2mm.