observable at one period of the year." As soon as the plant has done flowering, the flower-stalk, as in many other plants, bends down, rising again into an erect position when ripe, for the better dispersion of the seeds to a distance. Whether the leaf of the Wood-sorrel, or of one of the clovers is the ancient "shamrog" of Ireland, is a question which has led to much learned disputation, and which will be noticed more fully in the paper on Trefoils. 2. O. corniculáta (Yellow procumbent Wood-sorrel). -Stem branched; branches prostrate; stalks usually 2-flowered; leaves ternate; stipules united to the base of the leaf-stalks. Plant annual. This species, which has small yellow flowers, is not nearly so elegant a plant as the common Wood-sorrel. It is in flower from June to September, in shady woods in the south-west of England. Though so rare in Britain, it is a common flower in many countries of Europe, especially in the south, as in Spain and Italy. It is also found in Japan and Mexico, and in the latter country the flowers are much larger than in the English specimens. A yellowflowered sorrel, termed Oxalis microphylla, is very common in Australia; Mr. Backhouse says that it displays its lively blossoms in almost every grassy spot in the colony of Van Diemen's Land, and that its acid leaves resemble in form those of the clover. It is eaten in its fresh state by the natives to allay thirst, and when made into tarts is scarcely inferior to the fruit of the barberry. This traveller also found a white-flowered Wood-sorrel, O. lactea, generally dispersed over the colony, but not growing anywhere in sufficient quantity to be of any service. The Oxalis stricta is a yellow-flowered species, and is said to be naturalized in gardens near Penzance, and in fields near Northam, in North Devon. It differs from Oxalis corniculata in its more upright and less branched stem, in the greater number of its leaves, which, in some specimens, surround the stem in a whorl; in its flowers growing in an umbel, and in the absence of stipules at the base of the leaf-stalks. SUB-CLASS II.-CALYCIFLORÆ. Sepals distinct, or united; petals distinct; stamens inserted on the calyx, or close to its base. ORDER XXIII. CELASTRINEÆ.-SPINDLE-TREE TRIBE. Sepals 4-5, inserted on a fleshy disk, when in bud overlapping each other; petals equal in number to the sepals; stamens equal in number to the petals, and alternate with them: ovary wholly or partly sunk in the disk, 2-5-celled; fruit either a capsule of 2-5 cells opening with valves, or berry-like; seeds often enveloped in a distinct covering called an arillus. This Order consists of a large number of trees and shrubs, which are natives of the warmer parts of Europe, North |