Basic facts about the life form of the species are given on this page, based on PLANTATT which should be consulted for details of how the measurements were derived. 

Height: this is the height of terrestrial plants (cm). These measurements are intended to give a measure of the usual height of the plant and are not record maximum heights. For submerged aquatic plants the height measurement is replaced by length (cm). Heights and lengths of rosette plants are measurements of the leaf length rather than stem length. The diagrams show the distribution of values for all British and Irish species in blue and the value for the species in question in red.

Perennation: plants are described as annual, biennial or perennial. Most species fall into just one of these categories and for these the appropriate term is given under Primary Perennation. If there is variation within a species, the usual habit is given under Primary Perennation and the alternative under Secondary Perennation.

Woodiness: plants are categorised as woody, semi-woody or herbaceous.

Clonality: for a list of the categories used to describe the extent to which plants spread vegetatively by clonal growth (see below). As with perennation, a single category is given under Clonality – primary or if the species has more than one method of clonal spread, the categories are given under Clonality – primary and Clonality – secondary.


Categories of clonality

Little or no vegetative spread

Tussock-forming graminoid, may slowly spread

Tuberous or bulbous, slowly cloning by offsets

Detaching ramets above ground (often axillary)

Detaching ramets at or below ground

Detaching ramets on inflorescence

Detaching ramets on leaves (Hammarbya paludosa)

Detaching ramets on prothallus (Trichomanes speciosum)

Fragmenting as part of normal growth

Irregularly fragmenting (mainly water plants)

Plantlets formed on leaves (Cardamine pratensis)

Shortly creeping and rooting at nodes

Extensively creeping and rooting at nodes

Rhizome shortly creeping

Rhizome far-creeping

Clones formed by suckering from roots

Shortly creeping, stolons in illuminated medium

Far-creeping by stolons in illuminated medium

Tip rooting (the stems often turn downwards)