768 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. 



pollen, which ripens effectually. The Campanales are distributed over all quarters 

 of the globe. The Campanulacese are mostly natives of the North Temperate 

 Zone, the Lobeliacese of the South Temperate Zone and the Tropics. Some 

 Campanulacege are also found amongst the flora of the Arctic regions, and of high 

 mountains. The Stylidiaceae and Goodeniacese are confined to Australia. No 

 fossil remains have been discovered. The number of identified species now living 

 is about 1300. 



Alliance XLIX. — Ericales. 



Families: Dia'pensiacecß, Pyrolacece, Monotrojpacece, Lennoaceoe, Arbutacece, 

 RJiodoracece, Ericacece, EpacridaceGe, EmpetracecB, Ebenacece, Sapotacece. 



Perennial herbs, shrubs, and trees. Flowers actinomorphic and zygomorphic, 

 hermaphrodite, pseudo-hermaphrodite, monoecious, and dioecious. The floral-leaves 

 arranged in two 3-5 partite whorls. The lower whorl constitutes a calyx, the 

 upper a corolla. The petals are free in Pyrolaceas and Monotropacese; in the other 

 families they are coherent, at any rate at the base. The gynseceum is composed of 

 3-10 carpels; the ovary is superior, and 3-10 celled. The ovules arise from an 

 axile placenta. The audroecium is composed of one or more whorls of 4-5 stamens 

 each. In many cases some of the stamens are metamorphosed into gland-like 

 structures. The fruit is a capsule, berry or drupe. The embryo is erect, and 

 imbedded in the fleshy endosperm. 



The Diapensiacese and Pyrolacese (see figs. 277'''^' p. 273), are perennial herba- 

 ceous, or sutfruticose plants, which gTow in black humus, and have stiff, evergreen 

 foliage-leaves; the Monotropacese and Lennoacese are parasites or saprophytes 

 (see vol. i. p. 252), and are destitute of chlorophyll. The Arbutacese, Rhodoraceae, 

 Ericaceae, Epacridacese, and Empetraceaä are, for the most part, dwarf shrubs; only a 

 few are trees. Erica arborea, one of the Mediterranean Flora, when able to grow 

 without hindrance, attains the height of 8 metres. The branches of Ericaceae, Epa- 

 cridaceas, Empetracese, and of Loiseleuriaor Azalea jjrocmnbens, oneoi the Rhodoracege, 

 are thickly covered with stiff, rolled leaves (see vol. i. p. 303^). The species of the 

 genus Rhododendron have flat foliage-leaves (see Plate X.), as have also the 

 Arbutaceaä (see fig. 433^). The leaves of Arctostaphylos alpina, Azalea Pontica, 

 and A. inollis are green in the summer only, whilst most of the Arbutacea) and 

 Rhodoraceoe have flat, evergreen foliage. The Ebenacese and Sapotaceae exhibit, 

 in a large proportion of their species, arboreal growth and leathery foliage-leaves. 

 All the Ericales are distinguished for their solid timber. Some of the Rhodoraceae 

 have zygomorphic flowers; the rest of the Ericales have actinomorphic flowers. In 

 Loiseleuria, and in the Empetraceae and Epacridaceae, the androecium is composed 

 of one whorl; in the others it consists of two or more whorls. The anthers of 

 Arbutaceae and of many Ericaceae possess two peculiar horn-like appendages (see 

 figs. 433=^ and 433 ^ and figs. 216 9'ioii. p. 91). In Epacridaceae the anthers are 

 unilocular, and dehisce longitudinally; in Ericaceae, Arbutaceae, Rhodoraceae, and 

 Pyrolaceae they usually open by terminal chinks or pores (see p. 91, figs. 216 ^' ^' ^'^' ^^' ^'^). 



