Page 3 - Bulletin of the Cupressuss Conservation Project vol04_nr1 2015

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Bull. CCP 4 (1): 36-48 (6.2015) V.M. Dörken & H. Nimsch

Morphology and anatomy of pollen cones and pollen
in Podocarpus gnidioides Carrière (Podocarpaceae, Coniferales)

Abstract
Podocarpus gnidioides is one of the rarest Podocarpus species in the world, and can rarely be
found in collections; fertile material especially is not readily available. Until now no studies about
its reproductive structures do exist. By chance a 10-years-old individual cultivated as a potted plant
in the living collection of the second author produced 2014 pollen cones for the first time. Pollen
cones of Podocarpus gnidioides have been investigated with microtome technique and SEM.
Despite the isolated systematic position of Podocarpus gnidioides among the other New Caledonian
Podocarps, it shows no unique features in morphology and anatomy of its hyposporangiate pollen
cones and pollen. Both the pollen cones and the pollen are quite small and belong to the smallest
ones among recent Podocarpus-species. The majority of pollen cones are unbranched but also a few
branched ones are found, with one or two lateral units each of them developed from different buds,
so that the base of each lateral cone-axis is also surrounded by bud scales. This is a great difference
to other coniferous taxa with branched pollen cones e.g. Cephalotaxus (Taxaceae), where the whole
“inflorescence” is developed from a single bud. It could be shown, that the pollen presentation in
the erect pollen cones of Podocarpus gnidioides is secondary. However, further investigations with
more specimens collected in the wild will be necessary.

Key words: Podocarpaceae, Podocarpus, morphology, pollen, cone

1 Introduction

Podocarpus gnidioides is an evergreen New Caledonian shrub, reaching up to 2 m in height
(DE LAUBENFELS 1972; FARJON 2010). In older literature it is described as extinct in nature and only
recorded from the original collection. Thus, Podocarpus gnidioides was regarded as a doubtful
taxon (KRÜSSMANN 1983) and its systematic position among recent Podocarpaceae was therefore
unclear for a long time. However, today some stable populations (figs 6 & 7) are well known in the
south of the Baie de St. Vincent in South New Caledonia (ECKENWALDER 2009). Therefore the
present conservation state of Podocarpus gnidioides is described as “near threatened” (THOMAS
2010). Thus, enough vegetative material was available to solve the systematic position of
Podocarpus gnidioides based on molecular and also on foliar data (internal and external
microscopic leaf characters). Following current cladistic analyses of Podocarpaceae Podocarpus
gnidioides is placed within the Australis clade. Thus, Podocarpus gnidioides is closely related to
the New Zealand taxa Podocarpus acutifolius, Podocarpus cunninghamii, Podocarpus hallii,
Podocarpus totara (subclade Australis I) and to Podocarpus nivalis from New Zealand, Podocar-
pus alpinus and Podocarpus lawrencei from Australia (subclade Australis II) (KNOPF et al. 2011,
fig. 4). Podocarpus gnidioides has no close affinities to the other taxa native in New Caledonian as
e.g. Podocarpus decumbens, Podocarpus longifoliolatus, Podocarpus lucienii, Podocarpus novae-
caledoniae, Podocarpus polyspermus and Podocarpus sylvestris (ECKENWALDER 2009). Within the
Australis clade Podocarpus gnidioides is a sister taxon to the Australis I and Australis II subclades.

Podocarpus gnidioides is rare in cultivation and material (vegetative and fertile) is hardly available.
Thus, currently only limited data about morphology and anatomy especially about its cones are
available. Podocarpus gnidioides is dioecious as is also the case for nearly all other Podocarpus

1 Dr. VEIT MARTIN DÖRKEN, University of Konstanz, Department of Biology, M 613, Universitätsstr. 10, D-78457
Konstanz – veit.doerken@uni-konstanz.de, phone: +49-07531-88-2043, fax: +49-07531-88-2966.
2 Dipl.-Ing. HUBERTUS NIMSCH, St. Ulrich 31, 79283 Bollschweil, Germany, hubertus.nimsch@t-online.de, phone:
+49-07602-920309.

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