Utah Juniper vs Rocky Mountain Juniper

See associated observations: sample from both trees are shown together:
J. osteosperma sample on the left, J. scopulorum on the right.
samples taken from the observations associated with this post.

J. osteo......................................................J. scop.

single large seed.....................................2 (3) seeds

leaf margins finely...................................leaf margins entire/smooth
denticulate/serrulate

branchlets thicker .................................branchlets slender
stiff, chaotic.............................................less stiff, more elongate, sweeping

Range overlaps substantially, seems to be somewhat sorted by elevation but not entirely. I do not know how consistent this is. Temperature? UV exposure? Seasonal highs or lows? Soil? Moisture?

Posted on October 13, 2018 07:12 PM by chauncey chauncey

Observations

Photos / Sounds

What

Rocky Mountain Juniper (Juniperus scopulorum)

Observer

chauncey

Date

September 28, 2018 06:41 PM PDT

Photos / Sounds

What

Utah Juniper (Juniperus osteosperma)

Observer

chauncey

Date

September 27, 2018 09:27 AM PDT

Description

In photos comparing osteo and scop: Left sample is J. osteosperma, right is J. scopulorum.

osteo., = single seed, finely denticulate leaf margins.
J. scop branchlets thinner.

Comments

I go mostly by "pointiness" - scopulorum has acuminate to mucronate scale-leaf tips, the twigs tend to be pointed and slender and droop near the ends, and the whole tree is more likely to have a single trunk and a pyramidal crown. As for ecology, osteosperma generally occupies sites with higher drought stress, which can be linked to a variety of other factors - latitude, elevation, soil conditions or parent material.

Posted by chris_earle almost 5 years ago

Add a Comment

Sign In or Sign Up to add comments