Appomattoxia sp.

Friis, Else Marie, Crane, Peter R., Pedersen, Kaj Raunsgaard, Mendes, Mário Miguel & Kvaček, Jiří, 2022, The Early Cretaceous Mesofossil Flora Of Catefica, Portugal: Angiosperms, Fossil Imprint 78 (2), pp. 341-424 : 368

Appomattoxia sp.

Text-fig. 20a–d

Description and remarks. The material comprises three strongly compressed and lignitised fruits. SRXTM of one of the specimens did not provide any information on internal structure and there is no information on how the fruits were attached to the plant. The fruits are minute, elliptical to ovate in outline, 0.5–0.6 mm long and 0.3–0.35 mm wide ( Text-fig. 20a, b ). The fruit wall is thin with its surface covered by a thick cuticle bearing densely arranged, short, sometimes hooked trichomes, each with a broad base ( Text-fig. 20c, d ). The stigmatic area is indistinct, sessile and lacks trichomes. No pollen grains have been observed on the stigmatic region or on the fruit surface.

Affinity and other occurrences. The fossils are similar to fruits assigned to the fossil genus Appomattoxia in general shape, nature of the stigmatic region, thin fruit wall and the prominent trichomes that are sometimes coiled. The type species, A. ancistrophora E.M.FRIIS, K.R.PEDERSEN et P.R.CRANE from the Early Cretaceous mesofossil flora from Puddledock, Virginia, USA, has much larger fruits with trichomes that are longer and more distinctly and more regularly hooked ( Friis et al. 1995). The fruits from Catefica are more similar to fruits of Appomattoxia minuta E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN from the Torres Vedras mesofossil flora ( Friis et al. 2019a), but the trichomes are shorter, less prominently hooked and more densely arranged.

Pollen grains associated with Appomattoxia ancistrophora and A. minuta are identical to pollen of Goczania E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN. No pollen was found attached to the Appomattoxia fruits from Catefica, but Goczania stamens and pollen occur with the fruits in the Catefica mesofossil flora (see below). A piperalean affinity is inferred for Appomattoxia based on the combined pollen, fruit and seed characters ( Friis et al. 1995, for further discussion see also Friis et al. 2019a).

Figures

Text-fig. 20. Synchrotron radiation X-ray tomographic microscopy (SRXTM, a) and scanning electron microscope (SEM, b–h) images of fruits of Appomattoxia sp. (a–d) and anther and pollen of Goczania rugosa (e–h); Catefica locality, Portugal. a) Surface rendering of fruit in lateral view showing densely spaced hairs, some with delicate coiled tips; b) Fruit in lateral view showing short, densely spaced hairs and apical stigmatic region; c, d) Detail of fruit surface and hairs from fruit in (b); e) Fragmentary anther showing four pollen sacs; f) Proximal view of pollen grains from an abraded anther showing microechinate surface of pollen wall and clusters of small, spiny orbicules; g, h) Proximal (g) and distal (h) views of pollen grains from an isolated pollen sac, showing short colpus (h), tectate pollen wall and microechinate surface ornamentation. Specimens, Catefica 49-S174913 (a), Catefica 49-S107794 (b–d), Catefica 50-S170391 (e), Catefica 49-S170138 (f), Catefica 49-S170143 (g, h). Scale bars = 300 Μm (a, b, e), 100 Μm (c), 50 Μm (d), 6 Μm (f–h).