Macrocnemum
(from makros, long, and kneme, a leg; in reference to the long flower-stalks). SYN. Lasionema. ORD. Rubiaceae. A genus comprising about nine species of stove trees and shrubs, inhabiting tropical America and the West Indies. Flowers white or pink, in axillary and terminal panicles; pedicels bracteolate; corolla funnel-shaped or salver-formed; tube sub-elongate. Leaves opposite, petiolate. The only species yet introduced is the one here described. For culture, see Catesbaea.
M. jamaicense (Jamaica). fl. greenish-white, scented; corymbs on long peduncles. l. oblong-oval, petiolate, polished. h. 10ft. to 15ft., or sometimes a tree 30ft. high. Jamaica, 1806.
MACROGLOSSA STELLATARUM, or HUMMING-BIRD HAWK MOTH. This moth is of interest to gardeners, chiefly because of the part it plays in fertilising the young seeds in Honeysuckle and other plants in which the flowers have long, narrow tubes. In such flowers, the honey, which is the lure for insect visitors, is at the bottom of the tube, and is within reach only of those insects that have a long proboscis. Through this organ the honey is sucked up, but, to reach the latter, the head has to be thrust deep into the flower; and, in doing this, the insect carries off some of the pollen on its head or back. The parts thus dusted with pollen are almost certain to touch the stigma of the next flower visited; and the pollen grains adhere readily to the sticky surface of the stigma, whereon the insect's share in the work of fertilisation is completed. Some idea of the size, form, and markings of M. stellatarum may be formed from Fig. 498. The front wings are smoky, with a black central dot, and dark cross-bars. The hind wings are orange coloured, with the base and margin dark. The body is of a smoky hue, with black and white spots on the hinder part, where also there are black and white tufts on the sides, and a tuft of black hairs at the end of the body. These tufts are spread during flight, considerably increasing the apparent breadth of the body. The flight is very rapid, the moth dashing from flower to flower, remaining poised on the wing before each, while it sucks out the nectar, and unconsciously transfers the pollen from flower to flower. In mode of flight, in the loud humming noise that it emits while poised before a flower, and even in its general appearance, it so much resembles a Humming Bird as to well deserve the popular name of Humming-bird Hawk Moth. Like the bird named, it flies only by day, and most actively during bright sunshine, in this respect differing from most of the group of Hawk Moths. The caterpillar, like those of other Hawk Moths. The caterpillar, like those of other Hawk Moths, has a slender, sharp horn on the end of the body, resembling a short, erect tail. It is green, or pinkish-brown, sprinkled with white; the sides are bluish, with two dull white or pinkish lines along each. The caterpillar feeds on Lady's Bedstraws (Galium) of different kinds, and cannot be said to do any damage in gardens. When full fed, it burrows underground, and turns into a brown chrysalis.