Genus:
Juniperus
(Junipers)
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Genus:
Thuja (Cedars)
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Family:
Cupressacea (Cypress)
Idaho
species are either monoecious (pollen and seed cones on same plant) or dioecious
(pollen cones on one tree or shrub and seed cones on different plants) trees
or shrubs. The scale-like or needle-like leaves are either opposite or whorled.
Staminate strobili contain broadly peltate stamens bearing 2-6 pollen sacs.
Ovulate green to purple strobili bear 2-12 dry to fleshy scales. The flattened,
peltate (stalk attached in the middle rather than at the edge of the scale)
scales may be opposite or in whorls of three. The scales can be free from
each other or fused as in junipers (genus Juniperus). Pollen and ovule strobili
are born at the end (terminus) of branchlets. Some seeds are winged. Embryos
have 2 to 6 cotyledons. Juvenile leaves may differ from adult leaves.
Genus:
Juniperus (Junipers)
The
members of this genus are monoecious or dioecious evergreen shrubs or small
trees which bear scale-like, awl-like or needle-like leaves in 2 (opposite)
or 3 (whorled) ranks. The basal portion of the leaf is decurrent (forming
tiny wings) on the stem. The branchlets are terete or angled, but not flat
like the arborvitaes (genus Thuja). The three to five millimeter (one millimeter
= approximately 1/25 of an inch) staminate cones bear up to 16 stamens arranged
oppositely or in threes. The stamens are eccentrically peltate and bear three
to six pollen sacs. The ovulate cones are composed mostly of 3-8 scales that
are opposite or in whorls of three. They are fused and fleshy at maturity.
The ovulate or seed bearing cones are often referred to as "juniper berries."
The glaucous, blue to brown cones bear 1 to 5 wingless seeds. Each embryo
has two to six cotyledons. The indehiscent cones are readily eaten and digested
by animals. However, the hard seeds are not digested and are thus disbursed
in animal droppings.
Genus:
Thuja (Cedars)
General
information here.
Key to Family:
KEY TO THE SPECIES OF THE CUPRESSACEAE IN IDAHO
1a. Mature seed cones longer than wide, with flattened, dry, opposite, distinct
scales, not berry-like; twigs and branchlets appearing flat rather than round;
scale-like leaves opposite in 4 rows.- Western Red Cedar (Thuja plicata
Donn.)
1b. Mature seed cones spherical or almost spherical with 3 to 8 fleshy, fused
scales, cone berry-like; twigs and branchlets appearing round; scale-like
leaves in 2's or 3's. -Junipers (genus Juniperus ):
2a. The needle-like leaves in 3's, 5-19 mm long, not glandular; plant a low
shrub less than 2 meters tall.- Common or Mountain Juniper (Juniperus
communis L.)
2b. The scale-like leaves in 2's or 3's, less than 7 millimeters long, glandular
on back; shrubs or small trees at maturity more than 2 meters tall.
3a. Plant like a small tree with one cental trunk.
4a. Leaves in 3's with a prominent gland on back; seed cone bluish black,
7 to 8 mm in diameter, 1-3 seeded
Plants found in southwestern Idaho Western or Sierra Juniper ( Juniperus occidentalis
Hook.)
4b. Leaves in 2's with small gland on the back; seed cone 5-6 mm in diameter,
blue, usually one or 2 seeded; throughout Idaho Rocky Mountain Juniper (Juniperus
scopulorum) Sarg.