Abstract Detail

Paleobotany

Fossil Passiflora seeds from Gray Fossil Site (Pliocene, Tennessee, U.S.A.).

Passiflora, the passionflowers, includes over 500 species of plants distributed primarily in the neotropics today; under APG IV, the genus belongs within the pantropical subfamily Passifloroideae (16 genera, over 700 species), part of a broadly defined Passifloraceae. The fossil record of the subfamily is small, with most credible reports based on seeds assigned to Passiflora or Passifloroidesperma, the latter encompassing fossil seeds attributed to Passifloroideae that cannot be definitively assigned to an extant genus. A small suite of fossil seeds discovered at Gray Fossil Site (GFS), Pliocene, Tennessee, U.S.A., provides a new fossil record for Passiflora and Passifloroideae. The GFS seeds are typical of Passifloroideae in being small (ca. 5.5–6.4 mm long), compressed, and obovate, with a triangular apical appendage. The seed coat is reticulate-foveolate and palisade in structure; the endosperm is ruminate, as indicated by projections of the seed coat into the interior of the seed. The GFS seeds are similar in morphology to seeds of Passiflora incarnata (subgenus Passiflora, supersection Passiflora), a species widespread within and native to the eastern United States today. The GFS Passiflora seeds are the first credible report of fossil Passifloroideae from the eastern United States, and the first record of a primarily neotropical genus in the GFS macrofossil flora. Other fossil seed records of Passifloroideae are known from the Eocene of Colombia and the Eocene and Miocene of Europe. A review of the literature documenting fossil and modern passifloroid seeds indicates that, other than the GFS seeds, only Passiflora kirchheimeri subspecies bulgarica (Miocene, Bulgaria) can be attributed to Passiflora. The Bulgarian seeds have morphology consistent with placement in Passiflora supersection Cieca (19 species, New World, within subgenus Decaloba) and are not closely related to the GFS species.

1 - Paleontological Research Institution, 1259 Trumansburg Road, Ithaca, NY, 14850, United States

Keywords:
Passiflora
Passifloroideae
Neogene.

Presentation Type: Oral Paper
Session: PAL4, Paleobotany II: Cenozoic Paleobotany
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 2:15 PM
Number: PAL4008
Abstract ID:346
Candidate for Awards:None