RH E 



OR, BOTANICAL DICTIONARY. 



RHE 



moderate size; these are placed on long tables or boards, 

 and turned three or four times a day, that the yellow viscid 

 juice may incorporate with the substance of the root : for if 

 it be suffered to run out, the root becomes light and unser- 

 viceable ; and if they be not cut within five or six days after 

 they are dug up, the roots become soft, and speedily decay. 

 Four or five days after they are cut, holes are made through 

 them, and they are exposed to the air and wind, but sheltered 

 from the sun. Thus in about two months the roots are com- 

 pletely dried, and arrive at their full perfection. The loss 

 of weight in drying is very considerable, seven loads of green 

 roots yielding only one small horse-load of perfectly dry 

 Rhubarb. Dr. Falconer thinks, that if the following cir- 

 cumstances were attended to, British Rhubarb might equal 

 any of the foreign. First, a selection of the best pieces is 

 absolutely necessary. Secondly, the central part of every 

 piece should be cut out; for it is found by experience that 

 this, perhaps from its proximity to the sap, is moistest and 

 most subject to decay; and when any part comes into this 

 state, th'e infection soon spreads, and damages the whole 

 piece. Doubtless it is to avoid this, that the pieces of Rus- 

 sian Rhubarb have all holes of a considerable size cut through 

 their centre, which answers this more material purpose, as 

 well as that of hanging them up to dry; and the English, 

 Laving only the latter end in view, seldom make the holes 

 large enough to answer the former, at least not sufficiently 

 large to admit of removing the spongy and decaying parts. 

 Thirdly, the outside should be scraped, or rather rasped, as 

 the foreign Rhubarbs are: the neglect of this not only gives 

 it a shrivelled and mean appearance and colour, but is really 

 a great disservice, by obstructing the quickness of drying, 

 from the pores not being laid open for the herbaceous mois- 

 ture to exhale. Though the bark be stripped off, (he larger 

 pores, running mostly longitudinally, do not open laterally, 

 and of course the watery fluid, being confined, exudes very 

 slowly. Fourthly, it is probable that a prt-at improvement 

 might be made in the preparation of our Rhubarb, by acce- 

 lerating its drying. It was formerly thought that plants were 

 best dried in a slow and gradual manner, which is now found 

 to be a mistake; and that quick drying equally consists with 

 the safety of the vegetable substance, and the perfection of 

 its efficacious qualities. 



4. Rheum Compactum; Thick-leaved Rhubarb. Leaves 

 sublobed, extremely blunt, very smooth, shining and tooth- 

 letted. Roots large, divided into many fangs, yellow within. 

 They approach nearer to the foreign Rhubarb than any other, 

 both in shape and quality. Native of Tartary. It is propa- 

 gated in the same way as the first species, which see. 



5. Rheum Ribes ; Warted-leaved Rhubarb. Leaves very 

 blunt, somewhat wartletted, with spinulose veins underneath; 

 petioles flat above, rounded at the edge. Roots thick, fleshy, 

 running deeply into the ground. Found on mounts Libanus, 

 Antilibanus, Sinai, and Carmel. 



6. Rheum Tataricum ; Tartarian Rhubarb. Leaves cor- 

 date-ovate, entire, very smooth ; petioles half round, angular; 

 panicle grooved. Native of Lesser Tartary. 



7. Rheum Hyhridum ; Bastard Rhubarb. Leaves smooth 

 above, somewhat hairy underneath, sublobed, acute; sinus 

 narrowed at the base ; petioles obscurely grooved above, 

 rounded at the edge. Native of the north of Asia. 



Rhexia ; a genus of the class Octandria, order Monogynia. 

 GENERIC CHARACTER. Calix: perianth one-leafed, tubu- 

 lar, vetrieose at the bottom, oblong, with a four-cleft bor- 

 der, permanent. Corolla: petals four, roundish, inserted 

 into the calix, spreading. Stamina: filamenta eight, filiform, 

 longer than the calix, and inserted into it; antherae declining, 

 VOL. ii. 104. 



grooved, linear, blunt, versatile. Pistil: germen roundish ; 

 style simple, the length of the stamina, declining; stigma 

 thickish, oblong. Pericarp : capsule roundish, four-celled, 

 four-valved, within the belly of the calix. Seed: numerous, 

 roundish. ESSENTIAL CHARACTER. Calix: four-cleft. 

 Petals: four, inserted into the calix. Anthe-rce: declining. 



Capsule: four-celled, within the belly of the calix. The 



species are, 



1. Rhexia Virginica. Leaves sessile, lanceolate, three- 

 ribbed, serrate ; calices fringed with glands. This rises with 

 an erect stalk nearly a foot and half high, four-cornered, and 

 hairy. The stalk has two peduncles coming out from the 

 side opposite to each other at the upper joints, and is termi- 

 nated by two others ; these each sustain two or three red 

 flowers with heart-shaped petals, spreading open in the form 

 of a cross : they appear in June.- It is a native of North 

 America. This, and the next species, arc propagated by 

 seeds, which must be procured from the places where they 

 naturally grow. If the seeds arrive before the spring, and 

 be sown soon after in pots filled with good fresh earth, and 

 placed under a frame to guard them from frost, the plants 

 will come up in the following spring ; but if the seeds are not 

 sawn till that time they seldom appear in the first year. 

 When they are fit to remove,';plant part of them in an eastern 

 herder, and others in pots to be sheltered under a fiame in 

 winter. The second year the plants will flower, and may be 

 continued with care for three or four years. 



- 2. Rhexia Mariana. Leaves sessile, lanceolate, three- 

 ribbed, fringed with soft hairs ; hairs of the calix stellated. 

 This sends up an erect stalk about ten inches high. The 

 st.alk divides at top into two peduncles, spreading from each 

 other, having one or two reddish flowers on each, with a 

 single subswsile flower between them. Native of Maryland, 

 of Brazil, and Surinam. 



3. Rhexia Tricholoina. Flowers solitary, axillaiy, and 

 terminating; leaves sessile, opposite, lanceolate, hirsute; 

 stem frutescent. This and all the following species, coming 

 from the hotter parts of America, will require tender treat- 

 ment to be cultivated here. 



4. Rhexia Acisanthera. Flowers alternate, axillary, pcdun- 

 cled, five-cleft; stem firm and square, emitting many square 

 branches towards the top. Native of Jamaica. 



5. Rhexia Jussioides. Leaves alternate, ribbed, rugged 

 at the margin. This is a shrub, four feet high, found at 

 Surinam. 



6. Rhexia Glutinosa. Leaves opposite, three-nerved, even ; 

 flowers thyrsoid ; stem shrubby. A handsome plant, destitute 

 of pubescence ; but the calix and upper part of the leaves 

 extremely glutinous ; flowers copious, large, purple. Found 

 by Mutis in New Gianada. 



7. Rhexia Leucantha. Leaves opposite, cartilaginous- 

 toothletted, coriaceous, shining; branchlets four-cornered; 

 flowers terminating, ten-stamined. Native of Jamaica. 



8. Rhexia Purpurea. Leaves opposite, toothletted, cori- 

 aceous ; branchlets round ; flowers axillary, ten-stamined. 

 Native of Jamaica. 



9. Rhexia Uniflora. Leaves petioled, ovate, serrate; 

 flowers axillary, solitary, ten-stamined ; stem dichotomous. 

 Found at Cayenne. 



10. Rhexia Inconstans. Leaves ovate, hispid with close- 

 pressed bristles, hoary, ihree-nerved ; peduncles terminating, 

 one or two flowered ; calix rough, with spreading bristles. 

 This is a small low shrub, with diffused ascending branches. 

 Flowers purple, usually five-cjeft. Ryan remarks, that it 

 varies much in the number of stamina. He found it in Mont- 

 serrat, upon lava covered with Moss. 



6B 



