CUCURBITACEAE

cucurbitaceae, a botanical order of dicotyledons, containing 87 genera and about 650 species, found in the temperate and warmer parts of the earth but especially developed in the tropics. the plants are generally annual herbs, climbing by means of tendrils and having a rapid growth. the long-stalked leaves are arranged alternately, and are generally palmately lobed and veined. the flowers or inflorescences are borne in the leaf-axils, in which a vegetative bud is also found, and at the side of the leaf-stalk is a simple or branched tendril. there has been much difference of opinion as to what member or members the tendril represents; the one which seems most in accordance with facts regards the tendril as a shoot, the lower portion representing the stem, the upper twining portion a leaf. the flowers are unisexual, and strikingly epigynous, the perianth and stamens being attached to a bell-shaped prolongation of the receptacle above the ovary. the five narrow pointed sepals are followed by five petals which are generally united to form a more or less bell-shaped corolla. there are five stamens in the male flowers; the anthers open towards the outside, are one-celled, with the pollen-sacs generally curved and variously united. the carpels, normally three in number, form an ovary with three thick, fleshy, bifid placentas bearing a large number of ovules on each side, and generally filling the interior of the ovary with a juicy mass. the short thick style has generally three branches each bearing a fleshy, usually forked stigma. the fruit is a fleshy many-seeded berry with a tough rind (known as a _pepo_), and often attains considerable size. the embryo completely fills the seed. [illustration: fig. 1.--_bryonia dioica_, bryony. 1, part of corolla of male flower with attached stamens; 2, female flower after removal of calyx and corolla; 3, berries; 1, 2, 3 about nat. size.] [illustration: fig. 2. 1, male flower of cucumber (_cucumis_). 2, same, in vertical section, slightly enlarged. 3, stamens, after removal of calyx and corolla. 4, female flower. 5, horizontal plan of male flower. 6, transverse section of fruit. 1 and 4 nat. size.] the order is represented in britain by bryony (_bryonia dioica_), (fig. 1) a hedge-climber, perennial by means of large fleshy tubers which send up each year a number of slender angular stems. the leaves are heart-shaped with wavy margined lobes. the flowers are greenish, 1/2 to 3/4 in. in diameter; the fruit, a red several-seeded berry, is about 1/4 in. in diameter. many genera are of economic importance; _cucumis_ (fig. 2) affords cucumber (q.v.) and melon (q.v.) _cucurbita_, pumpkin and marrow; _citrullus vulgaris_ is water-melon, and _c. colocynthis_, colocynth; _ecballium elaterium_ (squirting cucumber) is medicinal; _sechium edule_ (chocho), a tropical american species, is largely cultivated for its edible fruit; it contains one large seed which germinates in situ. _lagenaria_ is the gourd (q.v.). the fruits of _luffa aegyptiaca_ have a number of closely netted vascular bundles in the pericarp, forming a kind of loose felt which supplies the well-known loofah or bath-sponge.