Basic Plant Knowledge: Life-Form after Raunkiær

Every gardener should be aware of this categorization, I do not see any advantage in using the technical terms, but the key facts are very useful.

 The Danish botanist Christen C. Raunkiær published this basic classification for plants around 1900 and since then it got extended and modified by various authors, but the key principle stayed the same. It subdivides the plants by the location of the buds during seasons with adverse conditions, i.e. cold or dry seasons. We will not look into the details and subdivisions, only the pretty basics.

1) Phanerophytes = Trees

These woody plants grow stems into the air and locate their resting buds on branches above the soil surface

2) Phaneroyphytes = Shrubs

These woody plants branch near the base of the stem and also locate their dormant buds on branches. So, the only difference between a shrub and a tree is that a shrub does not form a distinct trunk

3) Chamaephytes = Dwarf shrubs

These woody plants locate their buds near ground level, good examples are rosemary or lavender.

4) Hemicryptophytes = Perennials

These herbaceous plants have their resting buds at or near soil level. These buds are often covered with old leaves and snow to survive the winter. Most of the garden plants which grow year after year are part of this division, for example irises, daylilies or hostas.

5) Cryptophytes = Geophytes 

These herbaceous plants have their resting buds under soil level. This is often seen with perennials which bypass summer draught and winter cold in bulbs or rhizomes, as with daffodils or tulips.

 6) Therophytes = Annuals

Annuals are herbaceous plants which don’t possess resting buds and die in adverse conditions and rest in form of seeds, e.g. sunflowers. Usually these are fast growing species because they need to complete their lifecycle within one season. A lot of weeds and garden ornamentals are from this division. You can derive two thoughts from this fact: Firstly, you need to catch the weeds before they flower to reduce their population. Secondly, if you want to reduce planting costs you need to use plants which live longer than one season 😉

Final thoughts:

This only an excerpt of Raunkiær's work, reduced to the basic classification which should be useful to everyone. I think most of what is depicted goes without saying, but I find it quite useful to read the distinction from time to time. If you want to look deeper (e.g., aquatic plants or aerophytes) I advise you to do your own research, it’s worth it. If you have any questions, don't hesitate to ask and I'll try to clear up any confusion.