WY Native Tree ID

Foliage

• Scale-like, overlapping, hugging the branch?

  • Are the branches rounded or flattened?

• Needle-like, long slender?

  • Are the needles growing singly along the stem, or

  • Are there two or more needles attached together at the base by a paper sheath?

• Are the needles straight, curved, twisted?

• Are they very thin or very thick?

• Sharp or blunt at the tips?

• Flexible or stiff? Can you bend them between your fingers when holding them at each tip, or do they break?

• Color (may range from yellowing-green to bluish-green)

• Length (this is where it's handy to have a small ruler with you out in the field) - length is variable, depending on the environment

• Shape in cross-section (could be flat, round, or squared)

• Is there an odor when the needle or scale is crushed or broken?

• Are needles grooved along the mid-section, notched at the tip, or tapered at the base or tip?

• Notice how the needles grow along the stem

  • Do they radiate completely around the stem?

  • Do they all grow forward toward the tip of the stem?

  • Do they grow along the upper half of the stem only, or along the sides?

• Are there any white dots, resin or other gummy substances on the needles or scales?

• Are there white "stripes" on either side of the needle?

• Or a white "bloom" that can be easily rubbed off?

Bud

• Size - depends on times of the year - buds expand into new growth from mid to late spring/early summer. The rest of the year, buds should be visible.

• Shape (long, pointed, round, etc.)

• Color (uniform throughout the bud, or are the scale margins a difference in color than the rest of the bud scale?)

• Texture (smooth, hairy, rough, gummy)

• Solitary or multiple?

• Scales (do they peel back away from the bud, or do they lay close to the bud?)

Stem

• When the needle is pulled off of the stem, does it leave a leaf scar on the stem?

  • What shape is the scar?

    • Is it flat, concave, or raised?

    • Is it round or oval?

• When the needle is pulled off, does it leave a stalk or projection on the stem?

• Color

• Texture

• Odor when bruised or broken

• Are there any galls or other abnormal growths?

Cone

• Texture (woody, papery, thick, thin)

• Color (yellow, dark brown, green, reddish or purple)

• Size (length, width)

• Shape (round, long, narrow, oval)

• Are the cones "berry-like”, as in the Junipers?

• Cone scales - are they prickly at the tips of each scale, with a short, thin or thick sharp point?

• Are there "appendages" (bracts) hanging over each scale, like a separate piece?

• What is the location of the cone?

  • At the end of the stem or along the stem?

  • Upright or hanging?

• If no cones are present on the ground are there upright "stalks" still on the branches? (White fir cones disintegrate while still on the tree, leaving a central upright thin stalk)

Habit/Form

Foliage

Leaf arrangement:

• • Are there two leaves that are directly opposite each other on the stem? (opposite)

  • Are the leaves arranged on the stem one at a time, alternating sides? (alternate)

  • Are the leaves almost opposite each other? (sub-opposite)

  • Are there three or more leaves attached to the stem at exactly the same point? (whorled)

Leaf type:

• • Is there just one leaf blade (and leafstalk) for each bud? (simple leaf)

  • Or is there more than one leaf blade (and leafstalk) for each bud? (compound)

  • Palmately compound (leaflets arranged so the leaflets radiate from one central point)

  • Pinnately compound (three or more leaflets arranged along a central stalk - one set of leaflets per bud)

    • Evenly pinnate (an even number of leaflets on the stalk - 6, 10, 12, etc.)

    • Oddly pinnate (an odd number of leaflets - 7, 15, 21, etc.)

  • Bipinnately compound more than one set of leaflets per bud - all leaflets arranged up and down a central stalk

Leaf margin (edge of leaf):

• • Are margin edges smooth or toothed (serrated)? If toothed, to what degree? (very fine and tiny to very large and coarse)

  • Are teeth pointed or rounded? Do they point toward the tip of the leaf or straight out?

  • Are there teeth within teeth (doubly serrated)?

  • Are margin edges wavy or lobed (indented)? Are the tips of the lobes pointed or rounded? If rounded, are there thin 'bristles' or hairs at the tip of each lobe? How many lobes?

Overall leaf shape:

• • Egg-shaped (ovate), oval, heart, round, diamond, triangular, narrow, oblong, lance-like?

Shape of leaf tip (apex):

• • A long, pointed tip, or a blunt, short tip? Rounded, straight across, heart shaped?

Shape of leaf base:

• • Rounded, heart-shaped, wedge-shaped, and straight-across? Or are the two sides of the base uneven, unequal, and lopsided?

Venation:

• • Which way do the veins run?

  • Are there several main veins originating from the same point at the base of the leaf? (palmate venation)

  • Or is there one central vein, with the side veins parallel to each other and straight, or irregular and curved? (pinnate venation)

  • Is there a very fine network of veins? (reticulate)

  • Do the secondary veins curve and run parallel to the margin and the main central vein, starting at the base and ending near the tip? (arcuate venation, sometimes called parallel)

Miscellaneous Leaf Features:

• • Stipules: tiny leaf-like appendages at the base of the petiole

  • Glands: very tiny bumps on top of the petiole, at the base of the leaf or on the leaf veins. It may be the same color as the leaf or a different color

  • Petiole: Leafstalk - is the stalk smooth or hairy? Notice the length. What is the general shape? Flat? Roundish? Is there milky sap that exudes from the stalk when pulled from the stem?

  • Leaf Color: could range from yellow/green to red/purple to blue/gray. Is the leaf the same color beneath as above?

  • Leaf Texture glossy, shiny, or dull? Is it thin or thick? Is it rough, sandpapery or smooth? Is it wrinkled looking? Is the texture the same beneath as above? Are there tiny hairs anywhere? Over entire surface, only at veins, or beneath?

  • Odor: When the leaf is crushed or torn, is there a distinctive odor?

Stem

• Are there thorns, spines, or prickles? Large, thin, short, fat - what color are they, how thick are they? Are they very sharp, or not sharp at all?

• Are there noticeable lenticels (dots on the stem - breathing pores). Raised or sunken; what color? Elongated horizontally or vertically?

• Is the stem straight, or is it crooked or zig-zaggy? (Usually, the stems are zig-zaggy, also have a false terminal bud - the false terminal bud is not situated at the extreme tip of the stem. It is just a little to the side.)

• What is the texture of the stem? Smooth, hairy, sticky, flaky, peeling?

• Is there a white or blue “bloom” that you can rub off?

• Size - is the stem thin, thick, ribbed, and grooved? Are there ridges? Is it round or square?

• Color - of the outer bark and the inner bark.

• Is there an odor to the stem when it is scraped, bruised or broken?

• Notice if there are bits of bud scales still remaining at the terminal bud scale scars (the point on the stem that differentiates between last year’s growth and this year’s growth - several rows of scars encircling the stem - new growth will be tender and greenish, last year’s growth will probably be a little woody).

• Are there spur shoots? (tiny, short stems that are very knobby with lots of horizontal ridges - they hold the flowers and fruit and are extra sturdy to hold that weight.) They are a good indication that the plant has fleshy, heavy, fruit instead of a dry fruit.

• Is there a milky sap that exudes from a cut stem?

• Bark on trunk - note the color and texture. Is it smooth, knobby, corky, peeling? Do the ridges run in a diamond shape, or vertically?

Bud

• Buds are available for observation almost the entire year, except from bud break in the late spring to mid-summer. They develop in the axil of the petiole and the stem. In the winter, the bud is usually visible just above the leaf scar that is left on the stem after the petiole has fallen. A few plants produce a bud under the bark, within the base of the petiole; therefore the bud will be invisible in the summer, and will be in the center of the leaf scar in the winter.

• Are buds whorled (more than two at one point around the stem)?

• Are buds opposite each other on the stem, sub-opposite (almost opposite), or do they alternate along the stem (staggered)?

• Do the side (lateral) buds stick out, away from the stem, or are they pressed closely to the stem?

• Are they slightly stalked, or not stalked at all?

• Are they lateral buds positioned in a vertical position, or are they slightly lopsided, tilting to one side or another?

• Are they curved or twisted?

• Is there only one bud at each node, or are there two or more (collateral or accessory) next to each other at each node?

• Is there one bud directly above another at a node?

• Is the terminal bud all alone, or are there several lateral buds positioned closely to the terminal bud, making a cluster of buds at the terminal?

• Is the terminal bud a “true” terminal bud, or is it a “false” terminal bud? (A true terminal bud will be straight - a false terminal bud will be a little tilted to one side, and there may be a terminal branch scar near it, where the true terminal bud fell off, leaving a scar; sometimes this is very hard to determine.)

• Also notice: Color - shape (pointed, round, etc.) - texture (sticky, smooth, hairy, leathery, shiny) - size.

Bud Scales

• Do the scales overlap each other? (imbricate) There would be at least three scales in order to be imbricate.

• Are there just 2 scales (rarely 3) that just barely meet and do not overlap? (valvate)

• Some plants have only one bud scale (a single cap that fits over the bud and splits open when the bud expands in the spring)

• Is the bud ‘naked,’ meaning that there are no hard scales, just a pair of developing leaves covering the bud?

• Notice the arrangement of the scales around the bud. Are they:

  • Arranged on the bud in vertical rows of uniform ranks - one exactly above the other?

  • Arranged with the lowest scale centered directly over the leaf scar?

  • Arranged with the lowest scales paired at each side of the leaf scar?

• Does the color of the individual scale change near the scale margin (at the top of each scale)?

• Is there hair just on the scale margins, on the whole scale, or not at all?

• What is the general shape of each scale? Is it long, short fat, narrow? Is there a vertical ridge in the center of the scale?

• Are there remnants of old bud scales still attached at the base of the bud, from last year’s growth?

Leaf Scar