Abstract Detail


Stockey, Ruth [1], Rothwell, Gar [2], Gemmell, Jen [3].

Paleogene diversity of Araceae: A new species from the Eocene of Vancouver Island, British Columbia, Canada.

Two permineralized inflorescences, at least 37 mm long and 8 mm wide occur in marine were studied using the cellulose acetate peel technique. The inflorescences are cylindrical spikes with a pedicel (stipe) 14.5 mm long.  Each bears numerous, small, helically arranged, bisexual, sessile flowers with hooded tepals. The inflorescence axis is parenchymatous with numerous horizontal partitions of sclereids in the pith. Flowers have three fused carpels, each bearing a single orthotropous, basally axile ovule. Remnants of probable stamens are present outside the carpels; however, the inflorescences have undergone abrasion and degradation prior to fossilization and were probably senescent at the time of preservation. Anthers are missing, and pollen seen among the perianth parts of several flowers corresponds to that in anthers of Gynoplatananthus (Platanaceae), a common taxon at the site and that does not belong to these flowers. Flower structure is compared to those of other petalloid, spicate, bisexual flowers in the monocot families Acoraceae and Araceae (Alismatales). The number of carpels is similar to Acorus (Acoraceae), and Spathiphyllum (Araceae, Monsteroideae), while the number of seeds per locule differs from these two taxa. Single-seeded ovaries are common in Araceae, while those of Acorus contain several seeds, those of Pothos and Pedicellarum (Araceae, Pothoideae), also tricarpellate, have one seed with axile, basal attachment and a smooth testa like those of the fossils. Characters of this inflorescence and other permineralized taxa have been added to the morphological database for alismatid monocots, and show that these inflorescences are most closely related to Proto-Araceae. More fossil material will be needed to further elucidate evolutionary trends in basal Araceae.

1 - Department Of Botany And Plant Pathology, 4575 Research Way, Research Lab Building, Corvallis, OR, 97333, United States
2 - Oregon State University, Department Of Botany And Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331, United States
3 - Telus World of Science, Edmonton, AB, Canada


Presentation Type: Oral Paper
Number: PB5002
Abstract ID:572
Candidate for Awards:None

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