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.RETT 



&I)£ ^reas'urg at Botanp, 



083 



RETTI or RATI-WEIGHTS. The seeds 

 of Abrus preeatorius. 



RETUSE. Terminating in a round end, 

 the centre of which is depressed. 



RETZIACE.E. Three shrubs or under- 

 shrubs from South Africa — Retzia with 

 rather long erect verticillate leaves, and 

 two species of Lonchostoma with small 

 crowded ones,— all with sessile flowers, 

 which although not small are almost con- 

 cealed by the leaves, have been attached 

 by different botanists to Convolvulacece, to 

 Hydroleacem, or to Solanacece. Their tech- 

 nical characters are those of the latter 

 order, but their habit is so different that 

 they have been proposed by some as a dis- 

 tinct group under the above name of Ret- 

 ziacece. 



REVALENTA ARABICA. The prepared 

 farina of the Lentil, sold also as Ervalenta. 



REVEILLE-MATIN. (Fr.) Euphorbia 

 helioscopia and other species. 



REVENTA-"CAVALLOS. Isotoma longi- 

 flora. 



REVOLUTE. Rolled backwards— i.e. out 

 of the direction ordinarily assumed by 

 other similar bodies; as certain tendrils, 

 and the sides or ends of some leaves. 



REVOLUTIVE. When the edges are 

 rolled backwards spirally on each side, as 

 in the leaf of the rosemary ; a term of 

 aestivation. 



REWUSD, or RAWUND. Indian names 

 for Rhubarb. 



REYNAUDIA. A genus of grasses be- 

 longing to the tribe Agrostidece. The in- 

 florescence is in simple panicles, the spike- 

 lets of which are one-flowered ; outer 

 glumes compressed, cleft below the points, 

 with short bristles; flowering glumes one 

 half shorter, three-nerved ; pales with very 

 short bristles below their points, the lower 

 five-nerved, the upper one-nerved ; sta- 

 mens two ; styles two. Only one species 

 is described, R. flliformis, a native of San 

 Domingo and Cuba. [D. M.] 



REYNOLDSIA. A genus of Araliacem, 

 consisting of two trees from the islands of 

 the Pacific Ocean, with simply pinnate 

 leaves, and small flowers in compound ter- 

 minal or lateral panicles. They have the 

 entire calyptrashaped corolla of the Ame- 

 rican SciadophyUums, but differ from that 

 genus in foliage, in the perfectly consoli- 

 dated stigmas, and in the drupe consisting 

 of from eight to eighteen pyrenes. 



RHABABATH. An Arabian name for 

 the fruit of Ruscus aculeatus. 

 RHABARBARUM. Rheum. 



RHABDTA. The generic name of two 

 stiff branching erect shrubs three to four 

 feet high, with the habit of some Lyciums, 

 belonging to the Ehretiacece, and most 

 nearly allied to Ehretia itself- differing 

 mainly from that genus in the style being 

 entire instead of forked. R. viminea is 



very common in India, and is found also 

 in Ceylon and Borneo, always growing in 

 the rocky or sandy beds of rivers. It has 

 reddish twigs furnished with an abundance 

 of alternate spathulate leaves, and in their 

 axils a few small rose-coloured flowers dis- 

 posed in corymbs. Each flower has a five- 

 parted calyx with narrow segments, a 

 shortly tubular corolla with a five-lobed 

 border, five stamens arising from the tube, 

 and an ovary ending in a slender style with 

 a two-lobed stigma. The fruit is a scarlet 

 berry with four to six seeds. R. lycioides 

 is a Brazilian species growing in similar 

 situations, and very like the former in 

 habit, but having broadly lance-shaped 

 leaves. [A. A. B.] 



RHABDOCALYX. Cordia, 



RHABDOTHAMNUS Solandri is the sole 

 representative of a genus of Cyrtandraceoe 

 peculiar to New Zealand, forming a slender 

 twiggy much branched shrub, two to 

 four feet high, with opposite leaves, and 

 pretty yellow and red striped flowers. Calyx 

 flve-cleft ; corolla with a bell-shaped tube 

 and a two-lipped border; fertile stamens 

 four, the anthers united ; ovary broadly 

 ovate ; style long, slender, and curved to- 

 wards the apex. The shrub is found in the 

 northern island of the New Zealand group, 

 from the Bay of Islands as far as the east 

 coast. [B. S.] 



RHABDUS. The stipe of certain fun- 

 gals. 



RH.EO. A name proposed by Hancefor 

 the Tradescantia discolor, a commelynaceous 

 plant long since introduced into our stoves 

 from the countries bordering on the Gulf 

 of Mexico, and which differs from the other 

 Tradescantias in its dense umbels on very 

 short scapes from the midst of long broad 

 radical leaves, and in the ovules being 

 always solitary in each cell of the ovary. 

 There is little beauty in its flower, but it 

 is sometimes grown on account of the rich 

 purple colour of the underside of the leaves. 



RHAGADIOLTJS. A genus of cichora- 

 ceous Compositce nearly allied to Lap- 

 sana, readily recognised when in fruit by 

 theinvolucral scales, which are about eight 

 in number, being spread out in a star-like 

 manner, and the margins of each incurved 

 so as to clasp in its embrace one of the 

 cylindrical achenes of the outer row : so 

 that in looking at a flower-head with ripe 

 achenes, there appears to be nothing but 

 the involucral scales left. There are but 

 two species, R. stellatus and R. Eedypnois, 

 I the former common through the Mediter- 

 ranean region, the latter extending east- 

 wards to Affghanistan. Both are annual 

 weeds six inches to a foothigh, with lyrate 

 and toothed or sinuate radical leaves, and 

 numerous small yellow flower-heads, those | 

 situated where the branches fork being ' 

 sessile, the others stalked. [A. A. B.J 



RHAGODIA. A genus of Australian 

 shrubs or herbs belonging to the Chenopo- 

 diacece. They have alternate leaves, and 

 spicate bractless flowers with a five-parted 



