Fuchsia pollen from the early Miocene of New Zealand

Fossil pollen of Diporites aspis Pockna}l & Mildenhall, from the early Miocene of New Zealand, was examined by combined light, scanning, and transmission electron microscopy, in order to determine its relationship to extant Fuchsia pollen. Based on overall morphology, exine structure, exine surface sculpture, viscin thread morphology, and apertural features, the fossil pollen definitely can be considered to represent Fuchsia. Parallel studies of extant Fuchsia pollen indicate that a more precise identification of the fossils is not possible. With the examination of additional fossil material, it should be possible to learn a great deal about the timing of origin and migration of the genus Fuchsia, but not of its constituent parts. FUCHSIA iS a large genus of mesophytic shrubs that does not appear to have a close relationship with any other genus of Onagraceae (Berry, 1982). It is found primarily in mountainous regions of South and Central America (nearly 100 species) with a single, disjunct section (Skinnera) in Tahiti (one species) and New Zealand (three species). Based on a number of criteria, the genus is one of the least specialized in the family (see Berry, 1982). However, floral and fruit features, and especially the clear adaptations for bird pollination and seed dispersal, suggest that Fuchsia is (with regard to these features) highly specialized (Berry, 1982). The South American center of distribution of the genus and of Ludwigia, the sister group of all other Onagraceae, suggested to Raven and Axelrod (1974) that South America may have been the center of origin of the family. Cranwell ( 19 5 9) reported a badly eroded Fuchsia-like grain from Seymour Island in West Antarctica, but this report indicates only a superficial resemblance and cannot be taken as evidence of the existence of the genus or family there. Not surprisingly, in view of the minimal investigation of strata of the right age for such evidence, there are no records of Fuchsia poll Received for publication 10 October 1984; accepted without revision 15 December 1984. Research was supported by National Science Foundation Grant BSR-8315186 to Daghlian and Skvarla and BSR-8214879 to Raven. The able assistance of Mr. William Chissoe III is gratefully acknowledged, as is the use of the Noble Electron Microscopy Laboratory at The University of Oklahoma. 2 Current address: Dartmouth Electron Microscope Facility, Dartmouth College, Hanover, NH 03756. len from South America; indeed, the only documented fossil records for the genus are from New Zealand (Muller, 1981). Pollen of Fuchsia was reported from late Oligocene sediments of New Zealand by Couper (1960), although Jenkins (1971) has indicated the sediments are early Miocene age. Mildenhall (1980) subsequently reported Oligocene Fuchsia (see also Pocknall and Mildenhall, 1984). All of these reports are based on light microscopic examination, which gives only somewhat limited information and allows determination of probable affinity. With the various electron microscopic investigations of Onagraceae pollen (Skvarla, Raven and Praglowski, 1975, 1976; Skvarla et al., 1978; Praglowski et al., 1983; Nowicke et al., 1984; PatelS Skvarla and Raven, 1984), however, it has become clear that there are a number of additional pollen characters that are unresolvable with light microscopy, and which might permit unequivocal generic or even subgeneric identification. In this article, we report the results of detailed examination of a number of grains of Fuchsia from the early Miocene of New Zealand, as well as of pollen of extant species of Fuchsia. We have attempted to document both generic and subgeneric affinities and to consider the significance of this material to our understanding of the geologic history of Fuchsia and other Onagraceae in Australasia. MATERIALS AND METHODS-Fossil pollen samples were provided by the New Zealand Geological Survey. Single grain mounts were made of six Fuchsia specimens from 65.5 m