Alismaphyllites grandifolius (Penh.) R.W.Br.

Plant Fossil Names Registry Number: PFN002115

Act LSID: urn:lsid:plantfossilnames.org:act:2115

Author: R. W. Brown

Rank: species

Basionym: Majanthemophyllum grandifolium Penh.

Reference: Brown, R. W. (1962): Paleocene flora of the Rocky Mountains and Great Plains. – Professional Papers, United States Geological Survey 375: 1–119, 69 pls., link

Page of description: 52

Other combinations

Types

Original diagnosis/description

Leaf broadly ovate, about 9.5 cm. wide, and 11.2 cm. long from the base of the sinus to the apex; apex acute; margin entire; obscurely three nerved, the veins about 2–3 mm. distant, the chiefly obscure cross veins either wholly transverse or diagonal.

Emended diagnosis

Stockey, Hoffman and Rothwell (2021: Amer. J. Bot. 108(8): 1419, 1421):
Leaf petiolate, geniculum absent; lamina simple, entire-margined, elliptic to ovate or oblong, 2.9 to >20 cm long; apex acute to slightly rounded, some mucronate; base cuneate to obtuse or cordate. Petiole broad, ~2 cm wide, multi-veined, continuing into lamina as the midrib in basal third. Primary veins parallelodromous, of two orders, diverging from petiole or midrib at acute angles. Submarginal vein present. Transverse veins of one order, opposite percurrent. Higher-order veins mixed opposite/alternate, single diameter, anastomosing, forming rectangular to polygonal areoles; no freely ending veinlets.

Stratigraphy

Paleogene, Paleocene
Paskapoo Formation; late Paleocene; North American Land Mammal Age middle Tiffanian (Ti3); Caryapollenites wodehousei palynostratigraphic zone; magnetostratigraphic zone 26r; ~59 Ma.

[stratigraphy according to Stockey, Hoffman and Rothwell (2021: Amer. J. Bot. 108(8): 1419)]

as Eocene in Penhallow (1902: Proc. & Trans. Roy. Soc. Canada, Ser. 2 8(sec. 4): 54)

Locality

Canada
exposures along both banks of the Blindman River and the northwest bank of the Red Deer River in the area around their confluence southeast of the town of Blackfalds in south-central Alberta, Canada (52°21′18″N, 113°45′00″W)

[type locality according to Stockey, Hoffman and Rothwell (2021: Amer. J. Bot. 108(8): 1419)]

as Red Deer River, N.W.T. in Penhallow (1902: Proc. & Trans. Roy. Soc. Canada, Ser. 2 8(sec. 4): 54)