Juniperus (Cupressaceae)


Juniperus osteosperma
Thompson & Anderson SW Veg. Change


Juniperus osteosperma
Uppsala University


Juniperus deppeana C.Drew
UofAz Palynology

Plant:
Members of the Cupressaceae possess scale-like leaves appressed to the terminal twigs. Female cones may be woody or fleshy. Junipers (Juniperus) are common shrubs or short trees of temperate regions of the both hemispheres. Although the genus name Juniperus is frequently applied to this pollen type in North America, many other plant genera produce pollen of this type, so the term "Cupressaceae" is used in regions where other members of the plant family occurr.

Non-pappilate inaperturate types
Erdtman (1957)
Actinostrobis
Agathis
Ambrotaxus
Aurucaria
Arceuthos
Athorotaxus
Austrotaxus
Calocedrus/Libocedrus
Callitris
Chamaecyparis
Cupressus
Diselma
Fitzroya
Gnetum
Juniperus
Larix
Neocallitropsis
Pilgrodendron
Pseudotsuga
Taxus
Thuja
Thujobsis
Torrya
Widdringtonia

Pollen light micrograph:
Pollen grains 20 - 35 µm spherical to elliptical, without obvious aperture but with star-shaped depression visible in fresh pollen. Sculpturing gemmate and the gemmae (spherical elements) deciduous. Fossil pollen ordinarily split, forming the characteristic "pac man" shape.

Pollen scanning electron micrograph (SEM)
Individual gemmae composed of smaller spheres, the entire wall rough.

Production and Dispersal:
Wind pollinated with generally high production and moderate dispersal.

Preservation:
The splitting of the pollen grains apparently speeds the grains' deterioration, and juniper pollen is not well preserved. This poor preservation has lead to the common practice of lumping this pollen type (Cupressaceae) with that of the "Taxodiaceae" (papillate grains) and Taxaceae -- the "TCT" pollen type.

Fossil Occurrence:
Plant fossils (leaves, cones) are known from the early Mesozoic onward.

References:
    Erdtman, G. 1957.
    Pollen and Spore Morphology / Plant Taxonomy. Gymnospermae, Pteridophyta
    Bryophyta. Almqvist abd Wiksell. Stockholm.

Links

Owen K. Davis 12/99