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Tillcea. | XXX, ORASSULACER. 159 
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 3or4, Plants very small, with minute flowers . » l. TILLAA, 
Stamens twice as many as the petals (half of them sometimes 
without anthers). 
Petals united in a tubular corolla, longer than the calyx . 2, CoryLEDON. 
Petals free or nearly so, and spreading. 
Flowers mostly with 5 or 6 petals and sepals 3. SEDUM. 
All the flowers with more than 6, usually 10 or 12 petals 
and sepals ; ° . : . 4, SEMPERVIVUM. 
Among the dications en in our ay deeb guild’ the Crassulas, E'che- 
verias, Rocheas, and a few others, belong to this family, but by far the 
greater proportion form part of the Micoide@ and Cactacee, which are 
entirely exotic. 
I. TILLZGA. TILLAA. 
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. 358). Mossy Tillea—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 subulate. 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. £7. summer. 
II. COTYLEDON. COTYLEDON. 
Herbs, or succulent shrubs, with scattered leaves (rarely opposite in 
some exotic species), and flowers in terminal racemes or panicles. Sepals 
5, small. Petals combined into a single tubular or campanulate corolla, 
with 5 teeth or divisions. Stamens 10, inserted at the base of the corolla, 
but often adnate to the top of the tube. Carpels 5, each with a scale at 
the base. 
Taking this genus in the sense in which it was understood by Linnzus, 
it includes a considerable number of south-west African, besides several 
south European and central Asiatic ones, which, with our British species, 
are considered by some modern botanists as forming a distinct genus under 
the name of Umbilicus. 
1, ©. Umbilicus, Linn. (fig. 359). Wall Cotyledon, Pennywort, 
Navelwort.—Stock perennial, almost woody. Radical and lower leaves 
on long stalks, fleshy, orbicular, broadly crenate, and more or less peltate. 
Flowering stems erect, from 6 inches to a foot high, simple or slightly 
