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.
-
Erdtman, G. 1957.
Pollen and Spore Morphology / Plant Taxonomy. Gymnospermae, Pteridophyta
Bryophyta. Almqvist abd Wiksell. Stockholm.
Owen K. Davis 12/99