Platanus dissecta Lesq.

Plant Fossil Names Registry Number: PFN000568

Act LSID: urn:lsid:plantfossilnames.org:act:568

Rank: species

Reference: Lesquereux, C. L. (1878): Report on the fossil plants of the auriferous gravel deposits of the Sierra Nevada. – Memoirs of the Museum of Comparative Zoology at Harvard College 6(2): 1–62, 10 pls.

Page of description: 13

Illustrations or figures: pl. VII, fig. 12, pl. X, figs 4, 5

Types

Syntype UCMP1831, UCMP 1832, University of California Museum of Paleontology, Berkeley, USA
Figures: pl. VII, fig. 12, pl. X, figs 4, 5

Note: Inventory numbers and repository according to Huegele et al. (2020: Int. J. Plant Sci., 181(3): 326).

Lesquereux (1878: Mem. Mus. Comp. Zool. Harvard Coll., 6(2): 13–14) mentioned more specimens (= syntypes) belonging to this species from "Chalk Bluffs, California. Professor J. D. Whitney. More common in the same formation at Table Mountain, Tuolumne County. Voy's Collection." Three of them were figured by him (pl. VII, fig. 12, pl. X, figs 4, 5).
Two of figured specimens were revised by Huegele et al. (2020: Int. J. Plant Sci., 181(3): 326). They designated as lectotype that one figured by Lesquereux (1878) on pl. X, fig. 4 (UCMP 1831) and refigured that on pl. X, fig. 5 (UCMP 1831; Huegele et al. 2020: Int. J. Plant Sci., 181(3): fig. 2D).

Lectotype UCMP 1831, University of California Museum of Paleontology, Berkeley, USA
designated in Huegele, I. B., Spielbauer, R. & Manchester, S. R. (2020): Morphology and systematic affinities of Platanus dissecta Lesquereux (Platanaceae) from the Miocene of North America. – Int. J. Pl. Sci. 181(3): 324–341.
Plant Fossil Names Registry Number: PFN000569
Act LSID: urn:lsid:plantfossilnames.org:act:569
Figures: fig. 2A, B

Note: Originally figured by Lesquereux (1878: Mem. Mus. Comp. Zool. Harvard Coll., 6(2): pl. X, fig. 4).

Huegele et al. (2020: Int. J. Plant Sci., 181(3): 326) stated that the lectotype was figured by Lesquereux (1878) on pl. X, figs 4 and 5. But the latter is another specimen.

Original diagnosis/description

Leaves large, subcoriaceous, truncate or subcordate at the base, deeply three or five lobed; lobes narrow, lanceolate-acuminate, sharply toothed.

Emended diagnosis

Huegele et al. (2020: Int. J. Plant Sci., 181(3): 326–327):
Leaves simple, symmetric, commonly palmately three lobed to occasionally five lobed (rarely unlobed and ovate), with short to long petioles that are basally inflated. Lobes, when present, nearly evenly broad in the middle. Length of the central lobe (measured from the apex to the level of sinuses between lobes) 0.6–2.2 times the width of the lobe. Lobes ca. 50% of total leaf length. Central lobe length 39%–65% (typically 43%–55%) of total lamina length. Apexes straight, obtuse to acute. Bases cordate to cuneate or nearly truncate, sometimes decurrent below the basal primary vein axil. Primary veins three or five; actinodromous in leaves with three primary veins, palinactinodromous in leaves with five primary veins. Lateral or lobar, primary veins diverge suprabasally to sometimes basally. Angle between adjacent primary veins 257–477. Secondary veins pinnate, craspedodromous, uniformly curved to somewhat sinuous, five to nine secondaries arising from each side of the midvein and five to nine arising from the external side of each lateral primary; fewer secondaries arising from the internal side of lateral primaries. Tertiary veins oppositely percurrent. Higher-order veins forming a fine orthogonal reticulum. Margin serrate with rounded sinuses; teeth simple (usually with one tooth per secondary vein) to compound (with smaller teeth situated between larger teeth that terminate secondary veins). Tooth apexes acute, apiculate to rounded, sometimes glandular. Stomatal complexes vary from anomocytic to paracytic, sometimes to laterocytic. Trichome bases circular, mainly confined to regions near veins. Associated stipules prominent, foliose, roughly orbicular with six to ten weakly developed, usually acute and apiculate lobes that radiate from a central attachment scar. Six to ten radiating primary veins each terminate in a lobe, producing glandular tips on each lobe. Sinuses between lobes smoothly concave, shallow. Lobes have one to several fine, acute teeth with scalloped sinuses. Higher-order veins join to form a fine reticulum, comparable to that of the leaf blade, with simple, freely ending veinlets.

Stratigraphy

Neogene, Miocene
[age according to Huegele et al. 2020: Int. J. Plant Sci., 181(3): tab. 1]

Locality

United States
Table Mountain, California, ca. lat. 38°1.170′N, long. 120°25.966′W [according to Huegele et al. 2020: Int. J. Plant Sci., 181(3): 327 as is for the lectotype]

Lesquereux (1878: Mem. Mus. Comp. Zool. Harvard Coll., 6(2): 13–14) included in his new species more specimens of diferent origin. For their origin, he stated: "Chalk Bluffs, California. Professor J. D. Whitney. More common in the same formation at Table Mountain, Tuolumne County. Voy's Collection."

Plant fossil remain

macro- and meso-fossils-embryophytes except wood

Comments

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