This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The openness of the meadow as a whole causes the flowering of meadow and pasture plants to be less restricted to certain seasons than in the case of woods where more sun (later in the summer) is needed for fruition, e.g. for bulbous plants. So that on the whole, disregarding the differences in latitude, and their effect on different areas, meadow and pasture plants bloom far earlier than other types. Thus amongst Orchids the Green-winged Orchid is in flower before the Purple Orchid of the woods, as is the Spotted Orchid in front of the Marsh Helleborine, whose moister habitat retards its blooming.
As a whole, most meadow plants are perennials, though some, as Annual Meadow Grass, are annual. As part of the dominant vegetation of the earth this is quite natural, for the perennial has a far greater chance of succeeding than the annual, and the biennial than the annual.
As in all types of vegetation, the flowering periods of certain groups of plants are characteristic of certain months. Thus the Composites are, as a rule, late-flowering, the Autumnal Hawkbit lingering far on into winter even. The Grasses also flower rather late, usually between May and July. But Vernal Grass and Meadow Foxtail are to be found in flower in April. There are also phases of flowering. The spring is characterized by the Lady's Smock and Lesser Celandine, and some early Buttercups and Daisies. Later, the Cowslips, Clovers, Self-heal, Bugle, come on, whilst last of all, the Meadow Saffron revives the touch of spring when the thistles are specially in evidence.
In this connection the pupil may be asked to note all the flowers in season in each month, and compare the lists. Such lists kept each year show whether any season is backward or forward, and lists made in different counties show the range of variation owing to latitude, temperature, etc.