Nectary

Nectary, any part of the flower which secretes the saccharine exudation, designed to attract insects, known as nectar. The term is physiological, nectaries being formed in different cases from very various parts; but their position and form are always related to insect-pollination. In all cases, moreover, the nectary seems to consist of a group of rather large thin-walled cells extending to the surface of the organ. In the Labiatas (q.v.), the heath tribe, the oranges, and other cases, the nectary is a ring-shaped cushion, below the ovary, produced from the floral axis. In Cruciferas (q.v.) it is represented by four or six roundish glandular outgrowths from the axis, between the filaments. In Umbelliferas (q.v.) and Compositas (q.v.) it is at the base of the style, above the inferior ovary. In the Crown Imperial (Fritillaria imperialis) there are conspicuous white hollows, secreting nectar, at the base of each perianth-leaf. The small scales at the base of the petals of the buttercup lead by numerous transitional types to the tubular green petals of Helleborus, the spurred petals of the Columbine and curious hammer-headed hollow petals of the monkshood. In the rhubarbs the base of the filament of the stamen is the secreting organ; whilst in the order Gesneraceas a whole stamen is aborted into a nectary. The secreted nectar is sometimes, as in Salvia, held up by a circlet of hairs, or may collect at the bottom of the flower, retained by the perianth leaves; but in other cases special hollow receptacles known as spurs (q.v.) are developed by either the calyx or the corolla. These may either be themselves secretory, as in orchids, or may merely receive nectar secreted by other organs.