Fig. 367.—Montia.
Diagram of flower.
Portulaca (Portulaca): flower, epigynous or semi-epigynous; fruit, a pyxidium. The stamens vary in number, and are most frequently placed in groups (in consequence of splitting) opposite the petals.—Montia: the corolla is slightly gamopetalous, but cleft on the posterior side (Fig. [367]), and as a consequence of the larger size of the lateral petals, slightly zygomorphic; 3 stamens.—Calandrinia; Talinum; Anacampseros; Claytonia.
125 species; mostly in warm and temperate countries, especially the arid parts of S. Am. and the Cape. Montia fontana (Blinks) is a native plant. Portulaca oleracea is cultivated as a pot-herb in the south of Europe. A few species of Portulaca and Calandrinia are ornamental plants.
Order 7. Nyctaginiaceæ. The characteristic feature of this order is the single, regular, united, and often petaloid perianth, the lower part of which generally persists after flowering and embraces the fruit as a false pericarp. The upper portion is most frequently valvate and folded, or simply valvate in æstivation. The number of stamens varies. The free gynœceum is unicarpellate and has 1 ovule. The fruit is a nut, but becomes a false drupe, since the lower persistent portion of the perianth becomes fleshy (as in Neea, where this fleshy part is almost always crowned by the upper persistent part of the perianth. In the majority of the Mirabileæ the lower part becomes the dry anthocarp, while the upper petaloid part falls away after flowering). Finally, a peculiar involucre is formed around the flowers by free or united floral-leaves.—The majority are herbs, some are trees (Pisonia, etc.); Bougainvillea is a liane. The stems are often nodose and swollen at the nodes; the leaves are simple, penninerved, scattered, or opposite, without stipules. In some, the vascular bundles are scattered; stem anomalous.
Mirabilis; the structure of the stem is abnormal. Dichasial branching with continuation from the second bracteole, thus forming unipared scorpioid cymes. The perianth is petaloid, funnel-shaped, and has a folded and twisted æstivation resembling that of the corolla of the Convolvulaceæ; the upper coloured portion falls off after the flowering. Outside, and alternating with it, is a 5-partite, sepaloid involucre of 5 spirally-placed floral-leaves.—Oxybaphus; the involucre envelops 1–3 dichasial flowers.—Bougainvillea; the involucre is rose-coloured, 3-leaved, and envelops 3 flowers (placed laterally; the terminal flower wanting). The leaves of the involucre in Boerhaavia, Pisonia, Neea, and others are reduced to teeth or scales.
157 species; mostly in tropical countries, and especially S. Am. Species of Mirabilis (Am.) are ornamental plants. Theïn is found in Neea theïfera Oersted (discovered by Lund in Lagoa Santa, Brazil), which may be used as a tea-plant.
Order 8. Aizoaceæ. Only 3 whorls are found in the flower, which alternate with one another when their leaves are equal in number. The first is sepaloid, the third one the carpels, and the intervening one is either uncleft, in which case it is developed as stamens, or it is divided into a large number of members which then all become stamens (arranged in groups), or the outermost ones become developed as petals. The fruit is most frequently a capsule with several loculi. Most of the species are herbs with thick, fleshy stems, and exstipulate leaves. The structure of the stem is usually anomalous.
1. Aizoideæ have hypogynous or perigynous flowers with (4–) 5 perianth-leaves; stamens single, or (by splitting) in groups of 2–3, alternating with the perianth-leaves. The gynœceum (with 3–5 carpels) has 3–5 loculi in the ovary, and most frequently numerous ovules in each loculus, borne on the central placenta formed by the edges of the carpels. The fruit is a capsule. The inflorescences are dichasia and unipared scorpioid cymes.—Aizoon, Mollugo, Sesuvium, and others are herbs or bushes, most frequently hairy.