298 The Natural System of Botany. 



Cereus. The flower of this plant i-s nearly a foot in breadth 

 the outer leaflets being of a brown color, the inner yellow' 

 gradually fading into a pure white in the centre. They begin 

 to expand early in the evening, are in full bloom at midnight 

 and by daylight in the morning are quite decayed. 



At page 219, is a notice of the peculiar structure of the Cac- 

 tus-stem, and of its remarkable power of resisting heat and 

 drought. 



Order, Grossulace^j — The Gooseberry Tribe. 



By many botanists this order is considered to be nearly allied 

 to the last. The structure of the fruit is similar, and the leaves 

 are often converted into spines. The species are small shrubs 

 with alternate, lobed leaves. The most common and useful 

 are the several varieties of Gooseberry and Currant, in a flower 

 of either of which the characters of the order may be observed. 

 The calyx is small, five-parted, and frequently colored. The 

 petals are small, five in number, and the five stamens spring 

 from between them. The style is single, with two small stig- 

 mas, and the ovary is imbedded in the calyx tube. It is one- 

 celled, and contains a considerable number of ovules, attached 

 to two parietal placentae. This structure is easily observed by 

 cutting a ripe gooseberry in two lengthwise. 



All the plants of this order are natives of temperate regions. 

 Their fruit is generally of a pleasant acid flavor, and always 

 wholesome. Several species from Western America are culti- 

 vated for the beauty of their flowers, as the Crimson Goose- 

 berry (Ribes speciosum), and the Golden-flowered Currant 

 (R. aureum.) 



Order, Passifloraceje — The Passion Flower Tribe. 



u When the Spaniards discovered America, they found, 

 among other curious things, a flower, which they thought was 

 an allegorical representation of the sufferings of our Saviour. 

 In its anthers they saw his five wounds, in the three styles the 

 nails by which he was fixed to the cross, and in a column 

 which rises from the bottom of the flower the pillar to which 

 he was bound ; a number of little fleshy threads which spread 



