;g] 



El)t Crca^ur^ at SScftann. 



826 



ORYGIA decumbens, the only species of 

 this genus of Mesembryacece, is a small de- 

 cumbent much-branched spreading shrub- 

 by plant found in Arabia Felix, India, and 

 the Cape of Good Hope. It has roundish 

 and elliptical fleshy bluish leaves, and pur- 

 plish flowers. These have a five-parted 

 calyx, about twenty narrow entire petals, 

 numerous stamens partly cohering in bun- 

 dles, a five-celled ovary with numerous 

 ovules, and five narrow at length recurved 

 stigmas. The fruit is roundish, with five 

 angles and corresponding furrows. [A.S.] 



ORYZA. A genus of grasses belonging 

 to the tribe Oryzece. The inflorescence is 

 in panicles ; glumes two, not exactly oppo- 

 site ; outer pale ribbed. The seeds grow on 

 separate pedicels, which spring from the 

 main stalk, and each grain is usually termi- 

 nated by an awn or beard resembling that 

 of some kinds of wheat. Steudel describes 

 fourteen species, including 0. sativa, the 

 well-known Rice of commerce. This impor- 

 tant grain, which supplies food for a great- 

 er number of human beings than are fed on 

 the produce of any other known plant, is 

 supposed to be of Asiatic origin, though 

 recenttravellers in South America mention 

 fin-ding the rice-plant apparently in a wild 

 state on the banks of some rivers there. 

 Throughout the Chinese Empire and the 



Orj'za sativa. 



continent of India, as well as in all the 

 great islands in the Indian Archipelago, 

 Rice is the principal, and frequently the 

 only, food of the great mass of the popula- 

 tion. In the Southern States of America, 

 whence it has formed a valuable article of 

 exportation, its culture did not begin sooner 

 than a.d. 1700, when it is said to have been 

 accidental : 'A brigantine from the island 

 of Madagascar happened to put in at Caroli- 

 na, having a little seed-rice left, which the 

 captain gave to a gentleman of the name 

 of Woodward. From part of this he had a 

 very good crop, but was ignorant for some 



years how to clean it. It was soon dispersed 

 over the province, and by frequent experi- 

 ments and observations, they found out 

 ways of producing and manufacturing it 

 to so great perfection, that it is thought to 

 exceed any other in value.' (Library of 

 Entertaining Knowledge.) 



The Common Rice is a marsh-plant, and 

 can only be cultivated successfully when 

 the ground can be inundated during a cer- 

 tain period of its growth ; besides, it re- 

 quires a temperature of 60° to 80° Fahren- 

 heit to ripen it ; consequently, its cultiva- 

 tion in Europe is limited, being chiefly 

 confined to Lombardy. [D. M.] 



ORYZOPSIS. A genus of grasses be- 

 longing to the tribe Stipem, sometimes re- 

 garded as a section of Vrachne. [D. M.] 



OSBECKIA. A rather extensive genus 

 of melastomaceous plants, confined to tro- 

 pical Asia and Africa and the adjoining 

 islands. The species are mostiy herbs, 

 rarely shrubs, and bear clusters or short 

 racemes of usually small rose purple or 

 violet flowers upon the ends of the branch- 

 lets. Generally they maybe known by the 

 four or five lobes or teeth of the calyx 

 having bristle-like appendages between 

 them ending in a tuft of hairs. The petals 

 are obovate and equal in number with the 

 calyx-lobes, whiie the stamens are twice as 

 numerous, and have anthers opening by a 

 single pore, without any or scarcely any 

 appendage to the base of the connective ; 

 and the four or five-celled ovary is crowned 

 with bristles, and ripens into a capsular 

 fruit containing cochleate seeds. [A. S.] 



OSCHNAH. Alectoria arabum. 



OSCILLATING. Adhering slightly by 

 the middle, so that the two halves arenear- 

 ly equally balanced, and swing freely back- 

 wards and forwards. 



OSCILLATORI^E. A natural order of 

 green-spored Alga, with simple articulated 

 threads, or branched by a peculiar change 

 in one of the cells, which is diverted from 

 its course, or more rarely by the protrusion 

 on one side of the central cord, in conse- 

 quence of the rupture of the outer coat. 

 Articulations very narrow. Propagation 

 by zoospores where the mode of fructifica- 

 tion is known. The order contains a large 

 mass of the confervoid Alga. Some of 

 them are mere strata of threads held toge- 

 ther by a little jelly ; others form dense 

 gelatinous masses after the fashion of 

 Tremella. Iu very many of the species the 

 outer coat separates from the thread which 

 it encloses ; the end of it becoming lace- 

 rated, and the divisions reflected and curl- 

 ed ; and as this process takes place repeat- 

 edly, we have occasionally very beautiful 

 forms, either from the curious condition of 

 the torn end, or from the complication of 

 the several coats. In some species the 

 outer coat is extremely thick ; and if the 

 articulation is continued through it from 

 the central thread, we have the most ele- 

 gantly striated frond as in Petalonema. 

 Sometimes it is extremely gelatinous, and 



