mede] 



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728 



deciduous, of six violet leaves with a green 

 spot above the middle. [J. T. S.] 



MEDRINAQUB. A coarse fibre from the 

 Philippines, obtained from the Sago palm, 

 and used chiefly for stiffening dress lin- 

 ings, &c. 



MEDULLA (adj. MEDULLARY). The 

 pith ; that central column of cellular matter 

 over which the wood is formed in Exogens. 



MEDULLARY RAYS. The cellular 

 plates or processes which connect the pith 

 of Exogens with the bark, constituting the 

 ' silver grain ' of their wood. 



MEDULLARY SHEATH. A thin stra- 

 tum of spiral vessels formed immediately 

 over the pith. 



MEDULLOSE. Having the texture of 



pith. 



MEDUSA'S HEAD. Euphorbia Caput 

 Medusa ; also Cirrhopctalum Medusae. 



MEGACARP/EA. A genus of Cruciferce 

 of the tribe Thlaspidece, containing one or 

 two perennial herbs from the deserts of 

 Central Asia. They have deeply pinnatifld 

 and cut leaves covered with white woolly 

 hairs, and terminal racemes of small pur- 

 plish flowers. The pouch is very large and 

 flat, compressed contrary to the partition, 

 the valves orbicular, each with one seed. 

 M. poh/andra, the Roogee of Kumaon, is 

 remarkable in the cruciferous order for its 

 numerous stamens, from ten to sixteen in 

 number. [J. T. S.] 



MEGACLINIUM. A small genus of or- 

 chids of tropical Western Africa, remark- 

 able for the curious flattened sword-shaped 

 leafy rachis or flower-stalk upon which the 

 no less curious little flowers are seated in 

 a straight row along the middle on both 

 sides. It is closely related to Bolbophyllum, 

 with which, indeed, some orchidologists 

 unite it, the chief distinctions being that 

 in Megaclinium the posterior sepal is much 

 larger than the other two, and united to 

 them at the base, the lip is loosely articu- 

 lated with the base of the column, and the 

 four pollen-masses are all of the same size. 

 The flowers are of a greenish or yellowish 

 brown, spotted more or less with purple, 

 and have a fancied resemblance to little 

 frogs or toads, whence one species has 

 been named M. Bufo. The four or five 

 known species are all epiphytes, and have 

 creeping rhizomes, bearing pseudobulbs 

 furnished with leathery veinless leaves, 

 and radical flower-racemes. [A. S.] 



MEGALOS. In Greek compounds^large. 



MEGASEA. Saxifraga crassifolia, S. cor- 

 difolia, and their allies. 



ME I A. A Tahiti name for Musa paradi- 

 siaca. 



MEION". Less ; prefixed to the name of 

 an organ, indicates that it is something , 

 less than some other organ understood. 

 Thus meiogyras means but little rolled in- \ 

 wards ; and meiostemonous is said of aplant i 



whose stamens are fewer in number than 

 the petals. 



MEISSISTERIA. A Brazilian genus of 

 Melastomacece, comprising about half a 

 dozen species of small erect hairy herbs, 

 with nearly simple or but slightly branched 

 stems, small mostly sessile leaves, and 

 small axillary bunches of reddish or pur- 

 plish flowers. These latter have a calyx 

 with a free campanulate tube and four 

 lobes about as long as the tube itself ; four 

 petals ; eight stamens, of which only four 

 are fertile and have beaked anthers open- 

 ing by a broad pore at their ends; and a 

 filiform style ending in a punctiform stig- 

 ma. [A. S.] 



MELALEUCA. This name, derived from 

 the Greek melas, black, and leukos, white, 

 is stated to have been applied to a genus 

 of Myrtacem, in consequence of the trunk 

 of one of the species being black, and the 

 branches white. The genus consists of 

 trees or shrubs, natives of Australia and 

 the islands of the Indian Ocean, with alter- 

 nate or opposite flat or cylindrical leaves, 

 and yellowish purplish or crimson flowers, 

 sessile in spikes or heads. The calyx tube is 

 hemispherical ; there are Ave sepals and 

 petals; alternate with the latter are five 

 parcels of stamens; and the capsule is 

 three-celled, united with and enclosed in 

 the thickened tube of the calyx, which also 

 adheres to the branch supporting it. 



These plants are all of them aromatic 

 from the presence of a volatile oil. The best 

 known among them on this account is M. 

 minor or M. Cajuputi, the leaves of which, 

 after fermentation, are distilled for the 

 purpose of yielding the oil known as Caju- 

 put or Cajeput oil, which is green, and has 

 a powerful aromatic odour. It is valuable 

 as an antispasmodic and stimulant, and in 

 1S31 was recommended as a remedy for 

 cholera, in consequence of which the price 

 of the oil was enormously increased, and 

 its quality proportionately deteriorated. 

 It is more than doubtful if, even in the 

 pure state, it possesses any advantage over 

 any oil of a similar nature. The leaves of 

 this tree are used in China as a tonic in the 

 form of decoction, where also the bark is 

 made use of in the construction of boats 

 and roofs for houses. Numerous species 

 are grown as evergreen greenhouse plants 

 in this country, on account of the simpli- 

 city of their foliage and the splendour of 

 their clustered flowers. [M. T. M.] 



MELAMPODIUM. A genus of Compo- 

 site of the tribe Heliantliece, consisting of 

 coarse dichotomous annual or perennial 

 herbs, with opposite leaves, and rather 

 small flower-heads growing singly from 

 the forks of the stem. The involucre has 

 five outer spreading herbaceous bracts, 

 and Ave to ten inner ones enclosing as 

 many florets of the ray, which are ligulate, 

 female, and usually yellow. The receptacle 

 is convex or conical, scaly, with numerous 

 small tubular male florets. The achenes , 

 of- the ray are entirely enclosed in the per- 

 sistent and usually hardened inner bracts 



