T E T 



which it is divided below, and which form four fingle-feeded 

 ccUs. Its diameter is above an inch. The flelb, in the old 

 fruit at lead, is thin and rather leathery. The nuts, or ce Is, 

 are larsre, liard, undivided, gibbous at the outhde, angular 

 at the inner, moderately thick, or rather thin, %vhitifli, not 

 feparated from each other by any intermediate pulp. Re- 

 cettach central, ending in the fummit of the berry, producing 

 from its upper part four fhort umbilical threads. Seeds foli- 

 tary, pendulous, large, obovate, reddifli-brown. Skm 

 fimple, thin, coriaceous. Albumen none. Emhyo the ihape 

 of the feed, inverted, pale and whitiili. Cotyledons thick, 

 fleihy, flat on one fide, convex on the other, emarginate at 

 the infertion of the radicle, which is minute, feated withm 

 the notch of the cotyledons, at their upper end. 



TETRAGON, TSTpayovo-, formed from TElf'5^, /o«'-, a"d 

 y'MOL, angle, in Geometry, a quadrangle, or a figure with 

 four angles. 



Thus a fquarc, parallelogram, rhombus, and trapezium, 

 are tetragonal figures. 



Tetragon, in 4flrolos;y, denotes an afpeft of two planets 

 with regard to the earth, when they are diftant from each 

 other a fourth part of a circle, or 90°. 



The tetragon is exprefled by the charafter D . 



TETRAGONIA, in Botany, fo called by Linnsus, 

 from T=\-!6 and ymx, an angle, alluding to the quadrangular 

 figure of the fruit. The word is happily abbreviated from 

 Boerhaave's Tetragonocarpiis, which has the fame meaning. 

 —Linn. Gen. 252. Schreb. 340. Willd. Sp. PI. v. 2. 

 1023. Mart. Mill. Dift. v. 4. Ait. Hort. Kew. v. 3. 

 210. Juff. 317. Lamarck Illuftr. t. 437. Gaertn. t. 127. 

 and 179. — Clafs and order, Icofandria Pentagynla. Nat. 

 Ord. Succulents, Linn. Ficoideie, Jufi. 



Gen. Ch. Cal. Perianth fuperior, in four, occafionally 

 three or five, ovate, flat, rather deflexed, coloured, perma- 

 nent, deep fegments, revolute at the edges. Cor. none, un- 

 lefs the calyx be taken for fuch. Stam. Filaments twenty, 

 capillary, fliorter than the calyx, into whofe bafe they are 

 inferted ; anthers oblong, incumbent. Pi/?. Germen infe- 

 rior, roundifli, with four angles ; fl;yles four, awl-fhaped, 

 recurved, the length of the ftamens ; iligmas downy, running 

 along the ftyles. Perk. Drupa coriaceous, quadrangular, 

 with four prominent longitudinal wings, or points, the op- 

 pofite ones narroweft, not burfting. Seed. Nut folitary, 

 bony, of two or more cells, with oblong folitary kernels. 



Efl". Ch. Calyx with from three to five deep permanent 

 fegments. Petals none. Drupa inferior, angular. Nut 

 with feveral cells. 



Obf. Linnaeus remarks that the primary flower is five- 

 cleft, which led him to refer this genus to the order Penta- 

 gynla. But it only affords an inftance, among many others, 

 that his orders of Icofandria, like thofe of Polyandria, ex- 

 cept Monogynia and Polygynia, are beft refolved into one, 

 they being liable to frequent uncertainty, not only in the 

 fame genus or fpecies, but the fame individual plant. See 

 Tetracera. 



I. T. frulkofa. Shrubby Tetragoflia. Linn. Sp. PI. 

 687. Willd. n. I. Ait. n. I. (T. foliis hnearibus ; Mill. 

 Ic. t. 263. f. 2. Tetragonocarpus africana fruticans, foliis 

 longis et anguftis ; Commel. Hort v. 2. 205. t. 103.) — 

 Stem flirubby, eredt. Leaves linear. Fruit winged Na- 

 tive of the Cape of Good Hope. A greenhoufe plant in 

 England, ever fmce the time of bifhop Compton, flowering 

 in the latter part of fummer, and eafily propagated by cut- 

 tings, but not endowed with much beauty, or any other qua- 

 lity to render it popular. 'Thcjlem is flirubby, bufliy, with 

 round, altern.ite, leafy branches. Leaves alternate, feffile, 

 linear -oblong, obtufe, entire, revolute, downy and foft, an 



T E T 



inch or more in length, with axillary tufts of fmaller one$. 

 Flowers yellow, in fomewhat whorled leafy clufters. 



2. T. decumbens. Trailing Tetragonia. Ait. ed. i. v. 2. 

 177. ed. 2. n. 2. Willd. n. 2. " Decand. PI. Grafles, t. 23. 

 (T. foliis ovatis integerrimis, caule fruticofo decumbente ; 

 Mill. Ic. t. 263. f. I.) — Stem flirubby, downy, decumbent. 

 Leaves obovate. Fruit winged. — Native of the Cape of 

 Good Hope. A greenhoufe fhrub, cultivated by Miller in 

 1758. It differs from the former in the larger fize, and 

 broad obtufe form of its leaves, as well as in having a more 

 gliftening mealy furface, and more numerous axillary tufts of 



Jlowers. The Jlem is more or lefs decumbent, and clothed 

 with very foft denfe hairs. 



3. T. herbacea. Herbaceous Tetragonia. Linn. Sp. PI. 

 687. Willd. n. 3. Ait. n. 3. (Tetragonocarpus afri- 

 cana, radice magna craffa et carnofa ; Commel. Hort. v. 2. 

 203. t. 102.) Stem herbaceous, fmooth, decumbent. 

 Leaves ovate, ftalked. Flowers fomewhat corymbofe. Fruit 

 winged. Native of the Cape, cultivated by Miller. The 

 root is perennial, thick, fleftiy, and lobed. Herb fmooth, 

 fucculent, with many decumbent, branched, annual, leafy 



Jlems, and fcattered, ovate, more or lefs acute, entire leaves. 

 Floiuers yellow, generally five-cleft, larger, and more fhowy, 

 than in the two preceding, ftalked, partly axillary, partly 

 corymbofe. All our knowledge of this fpecies is derived 

 from Commelin's work, nor had Linnaeus any fpecimen in his 

 herbarium. The laft.-defcribed is fometimes, in gardens, 

 millaken for T. herbacea. 



4. T. hirfuta. Hairy Tetragonia. Linn. Suppl. 258, 

 Willd. n. 4. Thunb. Prodr. 87. — " Herbaceous, hairy, 

 procumbent. Leaves ovate, villous. Flowers axillary, 

 feffile, three together." — Gathered by Thunberg, at the 

 Cape of Good Hope. 



5. T.fpkata. Spiked Tetragonia. Linn. Suppl. 258. 

 Willd. n. 5. Thunb. Prodr. 87. — " Herbaceous, fmooth, 

 ereft. Lower leaves ovate ; uppermoft lanceolate. Flowers 

 raceniofe." — From the fame country as the laft. Thunberg. 

 We have feen no fpecimens of thefe two fpecies. It is re- 

 markable that the younger Linnaeus defines the Jlowers of 

 T. hirfuta felTile, whilft; Thunberg calls them ftalked. Pof- 

 fibly the latter confounded with his hirfuta, our decumbens, 

 of which there is a fpecimen, apparently gathered by him, 

 in the Linnasan colletlion. 



6. T. echinata. Hedge-hog Tetragonia. Ait. ed. i. 

 V. 2. 177. ed. 2. n. 4. Willd. n. 6. " Decand. PI. 

 GrafTes, t. 113." — Stem herbaceous. Leaves rhombeo- 

 ovate. Fruit prickly. — Native of the Cape, from whence 

 Mr. Maffon introduced it at Kew, in 1774. The root is 

 annual or biennial. Stem herbaceous, divided from the bafe 

 into feveral decumbent branches, hai'dly a foot long, angular, 

 from the dcsurrent footjalis, which are half the lengtli of the 

 fpreading fucculent leaves, each an inch long. Floivers pen- 

 dulous, on very fhort, axillary, folitary, thread-fhaped, pur- 

 fleflalis clothed with cryftalline globules. Calyx in three or 

 four fegments ; cryftalline without ; greenifh-yellow within. 

 Stamens only three or four. Germen triangular, flat under- 

 neath, its angles befet with numerous conical thorns. Styles 

 three. Nut of three cells. IVillden. 



7. T. expanfa. Horned Tetragonia. Ait. ed. 1. v. 2. 

 178. ed. 2. n. 5. Willd. n. 7. " Decand. PI. Grafles, 

 t. 114." Scop. Infubr. v. I. 32. t. 14. Thunb. Tr. of 

 Linn. Soc. v. 2. ■335. ( T. halimifolia ; Forft. Prodr. 39. 

 PI. Efcul. 67. T. japonica ; Thunb. Jap. 208,) — Stem 

 herbaceous. Leaves ovate-rhomboid ; tapering at the bafe. 

 Fruit with four horns. — Native of New Zealand, about the 

 borders of woods, in bufliy fandy places, as well as of the 

 Friendly iflands, and of Japan. Sir Jofeph Banks intryducecl 



it 



