Plate XXVII.
CAMPANULA PUSILLA. HÆNK.
The Dwarf Hair-bell or Bell-flower. Petite Campanule ou Campanule Naine. Kleine Glockenblume.
The Hairy-Leaved Alpenrose
(RHODODENDRON HIRSUTUM)
The Alpenrose is the commonest and best known of all the Alpine plants. It abounds almost everywhere; were it not so it would have become practically extinct years before, for it is gathered unmercifully. Nor are the visitors to Switzerland alone responsible for this. Every Sunday throughout the summer, crowds of the native peasants, both children and adults, may be seen returning home, each bearing in his arms an immense bunch of the favourite flower, and often with a second and smaller nosegay tied round the top of his alpenstock.
There are really two distinct species of Alpenrose, the Hairy-leaved (Rhododendron hirsutum), and the Rusty-leaved (Rhododendron ferrugineum) varieties, and a hybrid or cross between them is also less commonly found. Both varieties are low evergreen shrubs with thick leathery leaves which only fade after three or four years. Both have raised brown spots on the lower surfaces of the leaves, only they are much more numerous on the Rusty-leaved species, so that the under surface of the leaf is completely covered with them while they are only sparsely scattered on the leaf of the Hairy-leaved variety. They contain a balsam, and are thought to be of use to the plant in preventing its drying up. They may also assist in the absorption of water. The flowers of both species are admirably adapted for cross-fertilisation by the humble-bees which visit them. The stamens first mature, and not until the great part of the pollen is shed does the stigma lengthen and become ready for pollination. The long hairs growing from the stalks which bear the stamens interlock with similar hairs on the inside of the corolla, and thus effectively prevent the entrance of smaller insects which might visit the flower in search of the abundant honey, but which would fail to effect its fertilisation. The flowers of the species here illustrated are usually a little paler in colour, slightly smaller, and open a little later than those of the Rusty-leaved variety. The plant usually forms a lower and more thickly branched shrub, with rather shorter twigs. But the essential distinguishing features between the two are to be found in their leaves. The leaves of Rhododendron hirsutum are usually broader and less pointed, green underneath, and have well-marked hairs all round their edges. In Rhododendron ferrugineum the leaves tend to be narrower, darker green above, and brown underneath, and are entirely devoid of hairs, but have rolled back edges. Both species are found abundantly in rocky places between 4000 and 8000 feet, and flower in June, July, and August, and may be seen at their best in July. The Rusty-leaved variety seems to prefer a rather moister spot and may also be found on peat. It is most abundant on primary granitic rock, while the other species grows best on limestone.
Plate XXVIII.
RHODODENDRON HIRSUTUM. L.