Cedar Valley Arboretum & Botanic Gardens

Needle Eye

leave a comment »

I took a variety of identification courses in college.  Remembering all those plants was enough to make me go crazy at times!  I would make up alliterations, rhymes, sayings … any trick in the book to help me keep them all straight.

When it comes to conifers, how do you tell one from the other?  When placed side by side, they all start to just look like a bunch of Christmas trees after awhile!  Thankfully there are a few easy ways we can begin to differentiate.  We can identify trees many different ways, including: bark, fruit, growth habit and leaf form.

The good thing about conifers is that they are evergreen so we can still use their leaves for winter identification.  We might not think of the leaves and scales of our conifer trees as “leaves,” but they are.  Plant leaves are the above-ground organ specializing in photosynthesis, whether it is the frond of a fern, sheath of grass, palmate leaf of a maple or needles of a conifer.

We can group conifers by their leaf type or arrangement.

 

Scaled leaves.  If the conifer does not have needles, it probably has scaled leaves (see photo).  A familiar example for many Iowans is the arborvitae (Thuja).  The hedge surrounding the Arboretum’s Rose Garden is arborvitae.  Other scaled-leafed conifers include many varieties of juniper and cypress.

 

Clumped needles.  Conifer needles either grow clumped on the branch or are attached each needle separately.  All pine trees (Pinus) have clumped needles in two, three or five per bundle (also called fascicle), depending on the species.

Two: Jack pine, Mugo pine, Austrian pine, Red pine, Scots pine

Three:  Ponderosa pine (but sometimes two)

Five:  Limber pine, Eastern white pine

“Flat Fir and Square Spruce” is all you need to remember for the last two groups of trees.

 

Flat needles.  Fir trees (Abies) have flat needles with blunt ends.  They are often the common Christmas tree variety because the short needles are less likely to drop than other species.

 

Square needles.  Spruce trees (Picea) have pointed needles that feel square when rolled between your fingers.

See you in the gardens.

Advertisements

Written by cedarvalleyarboretum

January 7, 2010 at 9:59 pm

Posted in Uncategorized

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: