168 THE CRASSULA FAMILY. [Tittcto. 



XXX. CRASSULACEjE. THE CRASSUL'A FAMILY. 



Herbs or shrubs, with succulent leaves, all or only the upper 

 ones usually alternate, rarely all opposite, no stipules, and 

 flowers in terminal racemes or cymes. Sepals 3 or more, 

 usually 5, sometimes 15 to 20, cohering at the base. Petals as 

 many, sometimes united in a single corolla. Stamens as many 

 or twice as many, inserted with the petals at the base of the 

 calyx. Ovary superior; the carpels as many as the petals, and 

 free, usually with a small, flat scale at their base, and forming 

 as many distinct capsules, each containing several seeds attached 

 to the inner angle. Embryo straight, with a thin, fleshy 

 albumen. 



A numerous family, extending over the greater part of the globe, but 

 particularly abounding in south-western Africa and in the rocky districts 

 of Europe and central Asia. The exact concordance in number of the 

 parts of the flower of the different whorls forms the most prominent 

 character of the family, to which the succulent leaves give a peculiar 

 habit. 



Stamens 3 or 4. Plants very small, with minute flowers . . 1. TILL.&A. 

 Stamens twice as many as the petals (half of them sometimes 



without anthers). 



Petals united in a tubular corolla, longer than the calyx . . 2. COTYLEDON. 

 Petals free or nearly so, and spreading. 



Flowers mostly with 5 or 6 petals and sepals . . . .8. SEDUM. 

 All the flowers with more than 6, usually 10 or 12 petals and 



sepals . . 4. SEMPERVIVUM. 



Among the succulent plants in our greenhouses, the Crassulas, Echc- 

 verias, Rocheas, and a few others, belong to this family, but by far the 

 greater proportion of "succulents" form part of the Ficoidece and Cactacece, 

 which are entirely exotic. 



I. TILL3BA. TILL^A. 



Very small annuals, with opposite leaves, and minute flowers in the 

 upper axils. Sepals, petals, stamens, and carpels 3 or 4. 



Besides the European species, the genus contains several from North 

 America, central Asia, southern Africa, and Australia, most of them 

 amongst the smallest of flowering plants. 



1. T. muscosa, Linn. (fig. 359). Mossy T.The whole plant is seldom 

 more than 2 inches high, and usually but an inch, or even much less, 

 although much branched, and crowded with flowers ; it is usually of 

 a reddish colour, and slender, though succulent. Leaves narrow- 

 lanceolate or linear. Flowers solitary in each axil, or several together 

 in little clusters. Sepals lanceolate, pointed. Petals minute and subu- 

 late. Carpels with 2 minute seeds in each. 



On moist, barren, sandy heaths and wastes, in western and southern 

 Europe, extending eastward round the Mediterranean, and northward 

 to the Netherlands. Has been found in several of the southern and 

 eastern counties of England, but not in Ireland or Scotland. PI. summer. 



