Rafflesia, a remarkable genus of apeta-lous, exogenous plants, named in honor of Sir Stamford Raffles. While making a tour in the interior of Sumatra, Dr. Joseph Arnold, one of the suite of Raffles, was called aside by a native to see a fine flower, and was the first European to examine the largest flower known. A drawing was made, and, with portions of the reproductive organs preserved in spirits, sent to England, where Robert Brown described it as a new genus and called it in hou-or of those engaged in the discovery Rafflesia Arnoldi; since then three or four other species have been found, all smaller than the first, and this genus and a few others form the order Rafflesiaceoe, all of them parasites. The species of rafflesia are all natives of Sumatra and the neighboring islands, and parasitic upon the roots and branches of species of vitis related to the grape. The plant consists solely of a flower, subtended by a few bracts, and directly sessile upon the stem of its host. The flower first appears as a small knob upon the vine, which gradually enlarges, and at the end of several months the fully developed bud looks like a monstrous cabbage.
The perianth is tubular below, with five entire thick lobes; the throat of the flower is surrounded by a thick and fleshy ring; within the cup or tubular portion are the stamens or pistils. In B. Arnoldi the flower is flesh-colored, marked with yellowish white protuberances, and the interior of the cup is of an intense purple color. The flower measures fully 3 ft. across and weighs 15 lbs.; its cup is estimated to hold 12 pints. In this as in other species the flower gives off a most repulsive odor of tainted meat, which is however attractive to insects, large numbers of which hover about it, and as the plant is dioecious they no doubt aid in its fertilization. There are several plants of the order Rafflesiaceoe in South America and a solitary species in the United States, described by Gray as pilostyles Thurberi, found upon the Gila river in Arizona; this is parasitic upon a leguminous shrub (Dalea), and though of the same family and having the same habit of growth with the rafflesia just described, it is as remarkable for its minuteness as that is for its Titanic proportions, the whole plant being barely a quarter of an inch across.