ORDER DIPENTAGYNIA. 161 



fe 



names ; when they are of a round form, they are called Melon-thistles ; when more 

 cylindrical and erect, 7hrch-thisfles ; when creeping, with lateral flowers, Ccrcuaes ; 

 and when composed of a stem resembling flattened leaves, Pricklif-pears. Plants 

 of the Cactus tribe are mostly destitute of leaves, but the angular or flattened 

 stems often appear like a series of thick, fleshy leaves, one growing from the top of 

 another. The beautiful dye called cochineal is obtained from an insect of this name, 

 which feeds upon the Cactus cochinilUfer. The Cactus opuntia, or true prickly- 

 pear, is found native in the United States.* In Brazil, some of the Cactus family have 

 been known to attain the bight of thirty feet, with a circumference of three feet. 



226. The family Amy g claim comprehends the peach and 

 ahnond, of the genus Amygdalus, with the plmii, cherry, and 

 pomegranate. These, which were placed by Jussieu in his 

 order Rosaceie, or rose-like j^lants, seem very properly sepa- 

 rated. The characteristics of this tribe are a calyx five-toothed, 

 petals five ; stamens about twenty, situated on the calyx ; ovary 

 superior, one-celled. The fruit a drupe. Trees or shrubs. The 

 leaves and kernel contain prussic or TiydrocyaniG cwid. The 

 genus Prunus contains the various kinds of the plum, cherry, 

 and sloe ; according to ancient writers it was brought from 

 Syria into Greece, and from thence into Italy. "We have sev- 

 eral native species. The pomegranate (Punioa) is a shrubby 

 tree, a native of Sj)ain, Italy, and Barbary ; it flowers from 

 Jmie till September. The Greek writers were acquainted with 

 it, and we are told by Pliny that its fruit was sold in the 

 neighborhood of Carthage. It is cultivated in England and 

 the United States ; not for its fruit, which does not come to 

 perfection so far north, but on account of its large and beauti- 

 ful scarlet flowers, which render it an ornamental plant. At 

 Fig. Ii2, a^ is the flower of the pomegranate {Punica grana- 

 tum) ; h represents the stamens of the same, as adhering to the 

 calyx. The almond is a native of warm countries and seems 

 to have been known from the remotest antiquity. 



227. Order Dlpeiitagynia. — Signifies two and five pistils. 

 We find here the Pomacese {ivom. jyomum^ apple), or apple tribe. 

 This is included in Jussieu's Rosacese, or rose-like plants ; but 

 although the fiowers of the apple genus have a strong resem- 

 blance to that of the rose, the difference in the fruit seems to 

 render this division proper. In this tribe, the most important 

 genus is Pyrus, which contains the apple and pear. The varie- 

 ties of these fruits are the eflects of cultivation, not the prod- 

 uce of differt7nt species. By means of grafting, or inoculation, 

 good fruit may be produced upon a tree which before produced 

 a poorer kind. Jussieu divided his natural order Rosacea 

 into the following sections : Poinacem^ with fruit fleshy, like 

 the apple and pear ; Bosce^ having iirn-form calyces ; Amygdor 

 IcB, having drupe-like fruits. 



* For illustrations of this family, see Plate i., Figures 2, 5, and 7. 



226. Family Amygdalae — Prunus — Pomegranate — Amygdalus. — 227. Order Dipentagyuia — Poma* 

 ceae— Varieties by grafting— Order Rosacea divided into sections. 



