SYSTEMATIC BOTANY. 



ERICACEAE. This is an extensive order of 

 shrubs or under-shrubs, with leaves evergreen, 

 rigid, entire, whorled, or opposite, and without 

 stipules. 'The name of the. heath family,' as it 

 has been very appropriately remarked, ' conjures 

 up immediately the image of a number of narrow- 

 leaved plants, with globular, ventricose, or bell- 

 shaped flowers ; and we are apt at first to think 

 that the family is so natural a one as to require 

 very little explanation.' Did the order include 

 only the heaths, this would be the case ; for all the 

 heaths, differing as they do in some particulars, 

 may be recognised at a glance ; but as the order 

 includes the Rhododendrons, the Azaleas, and 

 Kalmias, besides several other plants which have 

 not so strong a family likeness to each other as 

 the heaths, it becomes necessary to point out 

 the botanical resemblances which connect them 

 together. The first and most striking of these is 

 the shape of the anthers each of which appears 

 like two anthers stuck together and the manner 

 of their opening, which is always by a pore or 

 round hole in the upper extremity of each cell. 

 The filaments also in all the genera grow from 

 beneath the seed-vessel, being generally slightly 

 attached to the base of the corolla. There is 

 always a single style with an undivided stigma, 

 though the capsule has generally four cells, each 

 containing several small seeds. The calyx is 

 four or five cleft, and the corolla is tubular, with 

 a larger or smaller limb, which is also four or 

 five cleft. The above are the connecting points 

 between the various genera which compose the 

 family ; but the differences are such as to require 

 a subdivision of the Ericaceae into the following 

 sub-orders : i. Ericece, or those most closely 

 resembling the true heaths, their fruit being 

 loculicidal, rarely septicidal or berried, and the 

 buds naked ; 2. Rhododendrea^ those allied to 

 the Rhododendrons, their fruits being capsular 

 septicidal ; the buds, scaly, resembling cones ; 

 3. Pyrolece, those allied to the winter-green of 

 our woods, and distinguished by having a minute 

 embryo at the base of fleshy albumen, the two 

 preceding having a cylindrical embryo in the 

 axis of the albumen, i. Ericece. This sub-order 

 may be arranged into two sections namely, the 

 true heaths (Ertcida), having bracteal pedicels 

 of flowers, the corolla of each flower being more 

 or less bell-shaped or globose, with a four-cleft 

 limb, a four-lobed calyx, and eight stamens ; and 

 the Andromedidce, which have the corolla more 

 globose, the limb five-cleft, the calyx five-lobed, 

 and ten stamens. In other respects both sections 

 are nearly alike ; both have a honey-bearing disc, 

 and both have the leaves, which are narrow and 

 leathery, slightly rolled in at the margin. The 

 stamens appear differently in the several genera ; 

 some being capitate, others ending in awn-shaped 

 horns ; in some they are concealed by the cdrolla, 

 in others they are exposed. The style, in some 

 of the genera, projects considerably beyond the 

 corolla, in others it is rather contracted. The 

 more familiar genera -are, the common heath of 

 our moors (Erica tetralix), common ling or heather 

 (Calluna vulgaris), and the Cape heaths, many of 

 which have glutinous, cylindrical corollas. The 

 genera Andromeda, Zenobia, the strawberry-tree 

 (Arbutus), the bearberry of our Highlands (Arcto- 

 staphylos uva-urst], and Gaultheria, frequent in 

 gardens, are illustrations of the second section. 



Plants belonging to this sub-order cover large 

 tracts of our own country, are common in North 

 and South America, and abound at the Cape of 

 Good Hope, which has supplied our gardens with 

 hundreds of the most beautiful species of Erica. 

 All of them possess bitter, astringent, and diuretic 

 properties ; and the berries of some, as well as 

 the flowers, have been used in dyeing. The 

 Arbutus is a very ornamental shrub, the berries 

 of which are edible, and may be used in the 

 preparation of a wine. 2. Rhododendrece. The 

 plants in this sub-order have all less or more 

 a resemblance to the well-known genus Rhodo- 

 dendron, the species of which have generally ever- 

 green leaves, and large showy flowers produced 

 in terminal corymbs. The calyx is small; the 

 corolla, large in proportion, bell-shaped, and 

 deeply five-cleft ; the stamens, five or ten ; the 

 capsule, five-celled and five-valved. The flowers 

 are generally purple or whitish, though in some 

 they are yellow, pink, or bright scarlet, as in the 

 Nepaul tree-rhododendron (R. arboreutri). The 

 genus Azalea is very nearly allied to the rhodo- 

 dendron ; but its species the Indian and Ameri- 

 can differ considerably in their inflorescence and 

 leaves ; the latter in some species being deciduous. 

 Kalmia and Menziesia are familiar garden genera ; 

 Ledum palustre, or wild rosemary, and the 

 Labrador tea-plant (L. latifolium), also rank under 

 this section, whose members have an extensive 

 range, being found abundantly in Europe, Asia, 

 and North America. They are chiefly inhabitants 

 of high cold regions, and in this particular agree 

 with the general habit of the order. The Rhbdo- 

 dendreas possess soporific properties R. crysan- 

 thum being used in gout and acute rheumatism. 

 The Azaleas are astringent, and some yield a 

 poisonous honey, well distinguishing these plants 

 from the true heaths, none of which are poisonous. 

 The honey which gave rise to symptoms of 

 poisoning in the Greek soldiers during the cele- 

 brated Retreat of the Ten Thousand mentioned 

 by Xenophon, was obtained from Rhododendron 

 ponticum and Azalea pontica, two ornamental 

 shrubs much cultivated in our gardens and 

 shrubberies. It has been observed that the 

 leaves and flowers of R. arbor eum poisoned the 

 cattle which partook of them in Kumaon ; and 

 the leaves of R. ponticum have poisoned sheep 

 and goats in this country. Some species yield a 

 resinous matter having a powerful and oppressive 

 odour. R. setosum is the Tsalu of the Sikkim 

 Bhoteas and Tibetans, who attribute the oppres- 

 sion and headaches attending the crossing of the 

 loftiest passes of the Eastern Himalaya to the 

 strongly resinous odour of this and R. anthopogon, 

 the Palu of the natives. The Rhododendrons 

 introduced by Dr Hooker from Sikkim form the 

 most valuable addition to our ornamental plants 

 that has been made for many years. R. nivale 

 occurs at elevations of from 16,000 to 18,000 feet 

 on the Tibetan frontier. For eight months of the 

 year, it is buried under many feet of snow; for 

 the remaining four it is frequently snowed and 

 sunned in the same hour. R. ferrugineum and 

 hirsutum are the roses of the Alps, and form a 

 shrubby belt on the Swiss mountains. 3. PyroUa. 

 This sub-order is well illustrated by the winter- 

 green (Pyrola), which is common in British woods. 

 The species of Pyrola are evergreen plants, with 

 white flowers, the corollas consisting of five distinct 



