Tips for Plant Identification

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The following tips for plant identification helps one develop a system of “looking.”

SOURCE: Trees and Shrubs of the Pacific Northwest by Mark Turner and Ellen Kuhlmann, Timber Press, 2014.

  1. GOAL: to get an overall impression of the plant.
  2. Try to examine several individuals to get a feel for the variability of individual plants.
  3. Think about seasonality: you may need to wait until the plant is flowering to identify it. Are the leaves present on the plant year-round? What are the fruits like? Does the entire plant die within one season (annual), or are is the plant alive for more than one season (perennial)?
  4. Be aware that some plants are easier to recognize than others, even for experts!
  5.  Observe and take notes on specific aspects of the plant, describing:
    • Where is it growing (habitat)? Is the plant in full sun or full shade? Are you in the mountains, at the seashore, or in the shrub-steppe?
    • How big is the plant?
    • What is the stem like? Single or many? Clumped together? Upright or lateral? stiff or weak? Are there any spines, prickles, or hairs?
    • How are the leaves placed on the stem? Mostly on the ground (basal)? All along the stem? Or both?
    • Leaf shape: Are they all the same shape? Is the leaf entire (simple) or divided into leaflets (compound)? How many leaflets in each leaf? Is the leaf needle-like?
    • Leaf texture: Does it feel soft, leathery, hairly, sticky, or spiny? How does the leaf top compare to the leaf underside?
    • Leaf attachment to the stem: Is it opposite, alternate (staggered), or whorled (spiral)? ; Is there a short “stem” (petiole) connecting the leaf to the stem?
    • What are the flowers like? Beware: flower color may be highly variable between individual plants and may change as the flower ages.
      • Count the sepals (outermost layer of a flower). Are the separate or fused?
      • Count the petals. Are all the petals the same shape (regular)? Are the petals fused together- if so- describe the shape.
      • Count the stamens. Notice how the stamens are placed inside the petals. Are they shorter or longer than the petals? Are they all the same height?
      • Describe the shape of the pistil. Open up the pistil and describe the inside chambers and placement of the developing seeds.
      • Where do the sepals, petals, & stamens attach to the ovary, making the ovary superior, inferior or, in-between
      • Describe if there are any missing parts to the flower (incomplete).Are either stamens or pistil lacking within a flower (imperfect). Radial or bilateral symmetry?
      • Is the flower solitary or part of an inflorescence (group)? Draw the pattern