omph] 



QLfyc Crca^ury at 23otau». 



812 



of which are two three or four sessile 

 anthers. The leaves are alternate or nearly 

 opposite, large broad and entire ; the flow- 

 ers in terminal panicles, intermixed with 

 narrow leaf-like or coloured bracts, each 

 hract having in its axil a small cyme of one 

 central female flower and two or more 

 lateral male ones, or sometimes all are 

 males. There are five species known, two 

 from Madagascar, and three from the 

 West Indies and tropical South America. 

 Amongst the latter 0. triandra has a white 

 juice, which turns black in drying, and is 

 said to he used either for making ink or 

 as glue ; and the seeds both of that species 

 and of 0. diandra are eatable, after extract- 

 ing the deleterious or poisonous embryo. 

 The 0. diandra especially, is cultivated in 

 St. Domingo and Jamaica, under the name 

 of Noisettier or Cobnut, from the reseni- 

 hlance of the flavour of the seeds to that 

 of the European nut. 



OMPHALOBIUM. The name of a genus 

 of trees and shrubs of the family Connara- 

 cece, met with in the tropical parts of Asia, 

 Africa, and America. The leaves are ter- 

 nate or pinnate : and the flowers in axillary 

 clusters, or crowded together in a panicle 

 at the end of the branches. They have 

 much the same structure as that of Conna- 

 rus, but differ in that the fruit consists of 

 five pods (fewer by abortion), which are 

 slightly stalked, one-celled, one or two- 

 seeded, and two-valved. Zebra-wood is 

 stated by Schombursk to he the produce 

 of 0. Lambertii, a native of Guiana. Guet- 

 tarda speciosa, a cinchonaceous plant, is also 

 stated to furnish this wood. [M. T. M.J 



OMPHALODES. A genus of herbaceous 

 plants, belonging to the Boraginacem, dis- 

 tinguished by having the four nut-like 

 seeds furnished with an inflexed margin 

 which renders them cup-shaped. They 

 are natives of Southern Europe, Asia Mi- 

 nor, and the Caucasus; and several species 

 are grown in English gardens, under the 

 name of Venus's Navelwort. O. linifolia 

 is a common border annual with linear 

 leaves, and white flowers tinged with blue. 

 0.verna,the Petite Consoude of the French, 

 is a charming plant with creeping shoots, 

 ovate heart-shaped leaves, and brilliant 

 blue flowers like those of the forget-me- 

 not This is a perennial, and a common 

 ornament of shrubberies and cottage gar- 

 dens. [C. A. J.J 



OMPHALODtUM. The central part of 

 the hilum, through which vessels pass into 

 the raphe or chalaza. 



ONAGRACE^. (Onagrariw, Epilobiacew, 

 Circieacea:, Onagrads.) A natural order of 

 calyci floral dicotyledons belonging to 

 Lindley's myrtal alliance of epigynous 

 Exogens, consisting of herbs or shrubs, 

 with simple leaves, and the parts of the 

 flower usually tetramerous. Calyx tubu- 

 lar, the limb usually four-cleft (sometimes 

 two, three, or six) and cohering in vari- 

 ous ways, the aestivation valvate; petals 

 usually of the same number as the calycine 

 segments ; stamens usually four or eight, 



epigynous, the filaments distinct; ovary 

 two to four-celled, usually with an epigy- 

 nous disc; ovules anatropal. Fruit succu- 

 lent or capsular, one to two or four-celled. 

 They inhabit chiefly temperate regions of 

 Europe, Asia, and America, and are found 

 sparingly in Africa. Some yield edible 

 fruits, as Fuchsia ; others furnish edible 

 roots, as (Enothera biennis ; and both 

 Trapa nutans and T.bicorms, remarkable 

 for their horned fruit, supply edible seeds. 

 There are about thirty known genera, and 

 upwards of 450 species. [J. H. B.J 



ONAGRAIRE. (¥y.~) (Enothera. 

 ONAGRES. (Fr.) Onagracecc. 



OXCIDIUM. One of the largest of the 

 genera of orchids, comprising upwards of 

 200 species, and exclusively confined to 

 tropical America. As many of the species 

 are found growing at great elevations m 

 the mountain regions, they do not, in cul- 

 tivation in this country, require such an 

 elevated temperature as might at first be 

 expected ; indeed, 0. Warczewiczii, which 

 grows on oaks in the mountains of Costa 

 Rica and Veraguas, at an elevation of 8,000 

 to 10,000 feet, where the thermometer 

 stands at 40° Fahrenheit in November, 

 actually perishes as soon as it descends 

 into the warm zone. In its botanical 

 features the genus comes extremely close 

 to Odontoglossuni. its flowers have similar 

 spreading sepals and equal-sized petals, 

 with the two lateral sepals sometimes 

 united beneath the lip, and the lip itself 

 continuous with the column and tubercled 

 or crested at its base. The chief distinc- 

 tion resides in the column being shorter, 

 and not narrowed at the base like that of 

 Odontoglossuni. 



O. Papilio is well known in the orchid- 

 houses of this country by the name of the 

 Butterfly-plant, a name applied to it on 

 account of the appearance of its flowers, 

 which are borne singly upon the ends of 

 very long slender stalks, and have the 

 petals and hind sepal long and narrow, 

 and the lateral sepals shorter and much 

 broader. It is a native of Trinidad and 

 Venezuela. In some species the racemes 

 or panicles of flowers are of very great 

 length. This is especially the case in O. 

 altissimunii a West Indian species, with 

 bright-yellow and brown-spotted flowers, 

 in which they are thirteen feet long; in 

 O. corynephorum , a Peruvian species, which 

 has twining scapes between fifteen and 

 twenty feet long, bearing numerous 

 flowers, which have dull-brown sepals, 

 pale einnamon-and-whitc petals, and a 

 deep crinison-andwhite lip ; and in O. 

 falcipetalum, a Venezuelan plant, which 

 has great scrambling panicles twenty 

 feet long, with large brown flowers as 

 much as three inches in diameter In a 

 great number of them the prevailing 

 colour of the flowers is yellow, usually 

 variegated, however, with other tints, but 

 in O. concolor the flowers are wholly yellow, 

 and very large. 



One section of the genus consists of 



