SYSTEMATIC BOTANY. 



and delicious fruits, of which the apple, pear, 

 quince, and service-berry are familiar examples. 



MYRTACE^E. The order consists of upwards of 

 60 genera, and about 1300 known species. They 

 are all trees or shrubs, with simple exstipulate 

 leaves, which are for the most part opposite, full 

 of transparent dots, and with an intra-marginal 

 vein round the edge. The substance of the leaf is 

 coriaceous, and the dots are glands, or cysts, full 

 of a fragrant volatile oil. The inflorescence is both 

 terminal and axillary, variable in its form, but 

 generally aggregate the flowers being regular and 

 united, of a white, red, or sometimes yellow colour, 

 but never blue. The tube of the calyx adheres to 

 the ovary, and is from four to eight cleft, persistent 

 or deciduous. The petals, which are rarely want- 

 ing, are equal in number to, and alternate with, 

 the segments of the calyx ; the stamens are in- 

 serted with the petals, and are twice as many, or 

 (usually) indefinite, and then arranged in several 



Pomegranate. 



series ; the anthers are two-celled, and burst longi- 

 tudinally. Fruit, baccate or capsular ; style and 

 stigma, simple ; many-celled, or one-celled by the 

 obliteration of the dissepiments of the carpels. 

 Seeds, generally indefinite, seldom few, and without 

 albumen. 



Among the edible fruits belonging to the order 

 may be mentioned the delicious guava, yielded by 

 several species of Psidium; the rose-apple and 

 jamrosade, produced by Eugenia and Jambosa. 

 Of spices yielded by the order, which are all more 

 or less aromatic, we have the clove, which is the 

 unexpanded flower-bud of the Caryophyllus aro- 

 maticus; all-spice, Pimento or Jamaica pepper, 

 the dried berries of Eugenia pimento; and also 

 the dried berries of the common myrtle. It is the 

 volatile oil found in the dots of the leaves, the 

 unexpanded petals, and in almost all the parts of 

 the plant, that gives to them their fine aromatic 

 fragrance. The pomegranate (Punica granatum} 

 forms a delicious fruit in warm countries ; the 

 pericarp or rind is used in the East as an astrin- 

 gent ; and the bark of the root is esteemed an 

 efficient anthelmintic. 



Some species of the beautiful genus Metrosideros 

 yield hard and heavy timber, which the South Sea 

 islanders prize for their clubs and other weapons 

 of war. The gum-trees of Australia (Eucalypti} 

 deserve special notice as among the most valuable 

 economical plants of our Australian colonies. They 

 are distinguished by a remarkable operculate calyx, 

 . 7 



and their bark separates in layers, giving rise to 

 the statement that the trees of Australia shed their 

 bark instead of their leaves in winter. Their 

 leaves often stand in a vertical position, and are 

 remarkably hard and coriaceous. These trees 

 grow to an enormous size, and yield very durable 

 timber. They supply the place of the European 

 oaks as a source of tannin. E, resinifcra yields, 

 on incision, an astringent matter, called Botany 

 Bay kino; while several others yield saccharine 

 matter. A peculiar red gum is contained in 

 cavities of the wood of E. robusta. The leaves of 

 some species of Leptospertmtm are used in Australia 

 as a substitute for tea. 



CycURBlTACEiE. This is a large and interesting 

 family of herbaceous plants, containing 56 known 

 genera, and about 300 species. The roots are 

 annual or perennial, fibrous or tuberous ; the stems 

 succulent, climbing by means of lateral tendrils 

 formed of the abortive stipules, and furnished with 

 large alternate, palmated rough leaves. The flowers 

 are usually unisexual. 



The Cucurbits are natives of all hot climates, 

 but are most abundant in India and South America ; 

 a few exist in the northern parts of Europe, and 

 some are found at the Cape of Good Hope. In 

 an economical point of view, the order is of con- 

 siderable importance, furnishing the well-known 

 esculents the cucumber, melon, gourd, pumpkin, 

 and calabash ; and the purgatives colocynth and 

 elaterium. The general properties of the gourd 

 family may be regarded as bitter and purgative 

 these qualities pervading more or less all the 

 species, and rendering their fruit either esculent 

 or purgative. The seeds of all are sweet and oily, 

 and from some a considerable quantity of fine- 

 flavoured oil may be expressed. The roots and 

 leaves are sometimes replete with a bitter drastic 

 juice. The fruit of many of the members grows to 

 an enormous size ; the calabash, for example, being 

 sometimes found six feet long and eighteen inches 

 in circumference. Gherkins are the fruit of the 

 common cucumber, pickled when in a young state. 

 The fruit of Lagenaria vulgaris is in common use 

 for water-bottles in the Greek islands and generally 

 in the East. It has probably given rise to the 

 clay water-bottles in form of a round bulb ending 

 in a long neck, which much resemble it in shape, 

 and to which the bottles in use all over the world 

 may be traced as modifications. Many of the 

 ornaments of ancient Egyptian architecture are 

 traceable in a similar manner to vegetable forms 

 peculiar to the region. 



CACTACE^E. The Indian figs, or Cacti, consti- 

 tute one of the most singular and interesting orders 

 in the vegetable kingdom. They are unique in 

 their forms and habits, having perennial succulent, 

 angular, or rounded spiny stems. In general, the 

 stems and branches are jointed ; the leaves are 

 either very minute, or altogether wanting, their 

 place being supplied by strong spines. They are 

 all natives of tropical America, but thrive well in 

 all hot, dry, and exposed places. Of the more 

 common genera, we may mention the following : 

 Mammillaria, so called from the pap-like tubercles 

 which cover its sub-cylindrical stem. Each tubercle 

 is crowned with a little tuft of radiating spines ; 

 and the flowers, which are sessile, are ranged in a 

 kind of zone round the plant. The melon cactus 

 (Melocactus communis), which has a more or less 

 globose stem, with alternate furrows and ridges, 



