1 42 FLOWERS OF GARDEN AND GREENHOUSE 
pairs to each pinna, and but one pair of pinnae to each leaf. Flowers 
purplish ; June to August. 
Mimosas are greenhouse subjects, and the species men- 
Coltivation. _ . 6 . . . 7 J . . „ r 
tioned are perennials, but M. pvdtca is usually grown as an 
annual. The compost that suits them best consists of equal parts of 
loam and peat with a little sand added. They are propagated by sowing 
seed in spring on a hot-bed. They are also increased by cuttings struck 
on a hot-bed. For this purpose young shoots should be inserted in sandy 
soil. No special instructions are called for. 
Description of The principal figure represents the upper portion of a 
Plate 70. stem of Mimosa pudica with the leaves expanded. Fig. 1 
shows how a leaf is depressed after irritation, the leaf-stalk being 
deflected close to the stem, and the leaflets closely packed together. Fig. 
2 is an unopened bud with its accompanying bract ; 3, is the same fully 
developed, with the long stamens and pistil extruded ; 4, is a section of 
the flovrer; 2, 3, and 4, of course, enlarged. 
SWEET PEAS 
Natural Order Leguminos2E. Genus Lathyrus 
Lathyrus (from the old Greek name for the Pea, Lathuros). A 
genus of about one hundred species of hardy climbing herbs, annuals, or 
perennials. The stems are smooth, angled, ridged, flattened. Leaves 
pinnate, certain of the leaflets being reduced to mere midribs which 
take the character of clasping tendrils; stipules large, shaped like half¬ 
arrow heads ( half-sagittate ). Flowers blue, purple, violet, rosy, yellow, or 
white; from the axils, solitary or in racemes. Petals broad, often very 
showy. The species are natives of the temperate regions of the Northern 
Hemisphere, South America, and of mountain regions in the Tropics. 
Lathyrus odoratus, the Sweet Pea, that is of so great 
importance in gardens large and small, is a native of 
Southern Europe, and appears to have been introduced from Sicily in the 
year 1700. It has been usually treated as half-hardy in this country, 
but is really quite hardy. Under cultivation the beauty of the flowers 
has been much increased by selection. The cheapest seed to be obtained 
to-day gives fine results compared with the natural type, but the large 
seed-raisers send out seeds that will produce magnificent blooms. 
L. latifolivs, the Everlasting Pea, is also European. By many it 
is regarded merely as a form of our native L . sylvestris, and therefore 
