Fig. 299.—The Sea Samphire
On the sandy shores of the south-western counties we may meet with the very local Four-leaved Allseed (Polycarpon tetraphyllum) of the order Illecebraceæ. It is a small plant, only four or five inches in height, with the lower leaves in whorls of four and the upper ones in opposite pairs. The flowers are minute, and are disposed in small dense clusters.
Another rare species is the shrub known as the English Tamarisk (Tamarix anglica), which is our only representative of the order Tamariscaceæ. There is some doubt, however, whether even this is indigenous to Britain, though it occurs in a wild state on the coast. It is a very twiggy shrub growing from six to ten feet in height, with minute scale-like, acute leaves, and slender spikes of small pinkish-white flowers.
We now pass to the large order of Leguminous plants, characterised by their stipuled leaves, and irregular papilionaceous flowers. The latter usually have five united sepals, five petals forming an irregular, butterfly-like corolla, ten stamens, and a superior ovary that develops into a pod.
Of these the Starry-headed Trefoil (Trifolium stellatum) is very partial to the sea shore, though it is sometimes found some distance inland. The genus to which it belongs is so called on account of its trifoliate leaves which are characteristic of the clovers, trefoils, and vetches, and which have stipules adhering to the petioles. The species under notice receives its name from the star-like arrangement of the long teeth of the hairy calyx. The stem of the plant is procumbent, usually about six or eight inches long, with cylindrical and terminal heads of yellowish-grey flowers.
Fig. 300.—The Sea-side Everlasting Pea
The Rough-podded Yellow Vetch (Vicia lutea) is somewhat rare, and occurs principally on very rocky coasts. In common with the other vetches it has pinnate, tendrilled leaves, without a terminal leaflet, one stamen free and the rest united into a bundle, and a long, slender, hairy style. Its stem is tufted and prostrate, averaging about a foot in length, the leaflets long and narrow, and the yellow flowers sessile and solitary. The teeth of the calyx are unequal, and the pods hairy and curved.