Keys

Life would be wonderful if we could identify all plants easily, merely from a series of photographs. Unfortunately life is rarely that simple it seems and, though this guide helps with the identification of many plants from photographs, some groups require closer inspection; a systematic way in which to separate similar-looking plants is required. Experienced botanists will be familiar with the idea of using keys to do this.

There are several different types of key that are used for identifying plants, but the most commonly-encountered and probably the easiest to use, are what are known as dichotomous keys. Such keys rely on setting out a series of identification criteria, which are laid out in numbered couplets; these couplets essentially offer you a choice, based on features of the plant that can be studied readily. You pick the one that is right for your plant, and so you proceed through the key until you come to a single species.

If you are completely at a loss in trying to identify a plant - or are new to the subject - you can work your way right through the keys, starting at the very beginning with the Primary Key on this page. Gradually, you will acquire knowledge which, in the future, will allow you to jump through the early stages, eventually turning straight to the single family or genus keys to confirm what you might already suspect.

Remember, even keys are not a one-stop fix for everything and they need to be based on something. Most keys include flower structure and so you will often find that the plant needs to be in flower for it to be identified in this way. While this can be frustrating when faced with a plant that is not in flower, the best way to proceed with plant identification is to learn the plants when they are in flower, then re-visit the same individuals at other times of year to learn what the fruits, winter twigs or other relevant parts might look like. However, given the right time of year, these keys should enable you to identify any plant you might come across, growing uncultivated in southern New Jersey.

Important Note: The keys only include species that have been recorded in southern New Jersey. Care should therefore be taken if using these keys outside of this area, as there may be other species present that are not included in the keys.


Primary Key to the Plants of Southern New Jersey

1. No flowers; reproduction by spores (ferns and their allies).
 2. Sporangia (spore cases) born under the scales of a terminal, cone-like spike. Stems conspicuously jointed, the nodes covered by toothed
   sheaths........................................................................................................................................................................................... Horsetails
 2. Sporangia not as above.
  3. Sporangia born in the axils of the crowded, lanceolate or subulate leaves, or of reduced scale-like leaves which form an erect spike.
   Plants moss-like, often branched and trailing over the ground............................................................................................. Clubmosses
  3. Sporangia not as above.
   4. Sporangia born at the base of slender, awl-shaped, rush-like leaves, which grow in a tuft from a round, fleshy base rooting in the
    mud. Plants submerged.......................................................................................................................................................... Quillworts
   4. Sporangia born on the back of a leaf (frond) in round, elongated or marginal patches (sori); or in a spike or cluster on the modified
    terminal (or middle) portion of the frond, or on a separate stalk arising from the ground (really a modified frond)................ Ferns
1. Woody trees and shrubs, or herbaceous forbs with true flowers present; containing stamens, pistils or both; reproduction by seeds.
 5. Trees with needle-like, usually stiff, leaves; fruit, an elongated, woody cone................................................................... Pines & Spruces
 5. Not as above.
  6. Trees with scale-like, leathery leaves, overlapping each other and covering the stem; or with short, needle-like leaves. Fruit, a spherical
   cone or a woody or fleshy berry............................................................................................................................ Junipers & Cypresses
  6. Not as above.
   7. Parts of the flower usually in threes or sixes, leaves mostly parallel-veined, often grass-like. Early leaves never opposite. In woody
    plants, stem not divided into bark, wood and pith............................................................................................ Key A - Monocotyledons
   7. Parts of the flower mostly in fours and fives, leaves net-veined. In woody plants, stem divided into bark, wood and pith, the wood in
    perennial species growing by annual layers just under the bark........................................................................... Key B - Dicotyledons