Plant ID Guide

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Introduction

Plant identification is the process of assigning the identity of an unknown specimen to a known taxon (a group of one of more populations of an organism/organisms that classifies a unit; plural: taxa). It involves matching certain specimen characteristics to a known taxonomic group and ultimately determining the species. Within a soil science context, plant identification is a useful tool that can reveal a wealth of information about specific site qualities and environmental conditions. For example, the presence, absence or abundance of a species can be indicative of a site's soil nutrient availability, moisture content, and ecological successional stage.

Plant Taxonomy and Classifications

Plant taxonomy is the science the identifies, describes, classifies and names plants. Plants are sorted into the following hierarchy, with an example of the family to which Asteraceae (which sunflowers belong to) are classified:

  • Kingdom: Plantae
  • Division: Magnoliophyta
  • Class: Magnoliopsida
  • Order: Asterales
  • Family: Asteraceae
  • Genus: Sunflowers (Helianthus), Dogfennel (Chamaemelum), Asters (Oclemena)
  • Species: Common sunflower, woodland sunflower, Calico aster, Blue-wood aster etc..
  • Variety: dwarf, giant, etc..

Our Local Climate

The Southwest Coast of British Columbia lies in a temperate rainforest zone, where climate is largely influenced by the Pacific Ocean and mountain ranges to the East. Characterized as having a mild climate year-round, summers in this region are warm with daytime temperatures hovering around 20 °C. This region also experiences the mildest winters in all of Canada, with temperatures that rarely drop much below freezing.

Precipitation rates vary widely due to BC's rugged and mountainous coastline. However, the region can be characterized as being "rainy", with average rainfall amounts ranging between approximately 1,000 mm to upwards of 2,500 mm annually.

Useful Identifying Characteristics

1. Inflorescence

Inflorescence is defined as a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed.

Simple Inflorescences

  • A raceme is an unbranched, indeterminate inflorescence with pedicellate (having short floral stalks) flowers along the axis.
  • A spike is a type of raceme with flowers that do not have a pedicel.
  • A racemose corymb is an unbranched, indeterminate inflorescence that is flat-topped or convex due to their outer pedicels which are progressively longer than inner ones.
  • An umbel is a type of raceme with a short axis and multiple floral pedicels of equal length that appear to arise from a common point. It is characteristic of Umbelliferae.
  • A spadix is a spike of flowers densely arranged around it, enclosed or accompanied by a highly specialised bract called a spathe. It is characteristic of the family Araceae.
  • A flower head or capitulum is a very contracted raceme in which the single sessile flowers share are borne on an enlarged stem. It is characteristic of Dipsacaceae.
  • A catkin or ament is a scaly, generally drooping spike or raceme. Cymose or other complex inflorescences that are superficially similar are also generally called thus.
Simple inflorescences

2. Leaves

Leaves can be one of the most telling components towards plant identification. They can be simple (a single leaf blade), or compound (several leaflets). Pay special attention to leaf shape, arrangement, edges (margin), and venation.

Leaf morphology no title

3. Bark and Trunk

Pertaining to tree identification, sometimes leaves and fruiting bodies can be too high off the ground to identify, or senesced specimens may be covered by snow or have blown away. In these cases, the colour and texture of bark can be a helpful identifying feature. Some qualities to pay attention to can be whether the tree has buttress roots, a straight or gnarled (knotted) trunk, multiple stems/trunks, or branches that begin low or high off the ground.

Click here for a printable guide to 20 common local species.

References

Climate of B.C. (2020). Retrieved July 07, 2020, from https://www.welcomebc.ca/Choose-B-C/Explore-British-Columbia/Climate-of-B-C

Environment Canada. (2019) Meteorological Service of Canada. Canadian Climate Normals. 1981-2010 Climate Normals & Averages.

Glossary of leaf morphology. (2020, June 18). Retrieved July 07, 2020, from https://en.wikipedia.org/wiki/Glossary_of_leaf_morphology

Identifying native plants. (2018). Retrieved July 07, 2020, from https://www.sciencelearn.org.nz/resources/2634-identifying-native-plants

Inflorescence. (2020, June 27). Retrieved July 06, 2020, from https://en.wikipedia.org/wiki/Inflorescence

Moore, K.A., and. L.K. Bradley (eds). 2018. North Carolina Extension Gardener Handbook. NC State Extension, Raleigh, NC. <http://content.ces.ncsu.edu/3-botany>

Plant identification. (2019, June 09). Retrieved July 07, 2020, from https://en.wikipedia.org/wiki/Plant_identification

Plant taxonomy. (2020, June 27). Retrieved July 07, 2020, from https://en.wikipedia.org/wiki/Plant_taxonomy