X Y S 



lijrht on this hitherto little-known, and ill-defcribed, genus 

 of plants. Could they all be compared together, even m a 

 dried ftate, we have no doirbt that their fpecilic charaders, 

 and the principles on which they are founded, would derive 

 confiderable improvement ; and that Xyris, whofe generic 

 marks are fo well ellablifhsd, would afford a beautiful dif- 

 play of clear and precife fpecific difcrimination. Whether 

 the leaves of any of the fpecies be really toothed, in a livmg 

 Rate, we have confiderable doubt. Their foliage partakes 

 greatly of the cellular texture, fo remarkable in the neigh- 

 bouring genus Erincaulon ; with which alfo they clofely 

 accord in inflarefcence, and general habit. Mr. Brown, in 

 his Prodromus, has elucidated both thefe genera, as far as 

 concerns their numerous New Holland fpecies, with in- 

 finitely more fuccefs than any other botaiiift ; the one genus 

 having previoufly been fcarcely better underllood than the 

 other. 



XYSMALOBIUM, from fucr^.x, ajlrip, or narrow Jlired, 

 and X'.Ba; a pod, alluding to the (hreddy coat of the feed- 

 veffel, which is very peculiar. — Brown Tranf. of the Wer- 

 nerian Soc. v. 1.38. Afclep. 27. Ait. Hort. Kew. 

 V. 2. 79. — Clafs and order, Pentandria Digynla. Nat. Ord. 

 Contorta, Linn. Apocinea, Juff. jljdepiadea. Brown. 



Gen. Ch. Cat Perianth inferior, of one leaf, in five 

 deep, lanceolate, acute, permanent fegments. Cor. of one 

 petal, in five deep, ovate, fpreading, rather oblique feg- 

 ments. Crown of the ftamens in a (ingle row of ten deep 

 fegments ; five of them flefhy, roundifh, oppofite to the 

 anthers, fimple at the inner fide ; five intermediate ones 

 fmaller. Stam. Filaments fcarcely any ; anthers five, each 

 tipped with an ovate bluntifh membrane ; maffes of pollen 

 ten, comprefTed, fmooth, pendulous, with rather broad con- 

 nefting proccfTcs. P'tjl. Germcns two, ovate, pointed ; 

 ftyles very fiiort ; common (ligma pointlefs. Peru. Fol- 

 licles two, inflated, clothed all over with numerous, long, 

 fleoder, tapering, hairy, filamentous procelTes. Seeds nu- 

 merous, imbricated, crowned with filky down. 



EIT. Ch. Maffes of pollen ten, fmooth, pendulous. 

 Crown fimple, in ten deep fegments, the intermediate ones 

 minute. Corolla fpreading. Follicles ffiaggy. 



A genus of upright flirubs, with oppofite, fometimes al- 

 ternate, leaves. Umbels lateral, either axillary, or between 

 the footjlalks. Flowers rather large ; the limb of the 

 corolla fometimes bearded. Only two fpecies are at pre- 

 fent known, both natives of fouthcrn Africa. 



1. X. undulqlum. Waved-leaved Xyfmalobium. Dryand. 

 in Ait. n. 1. (Afclepias undulata ; Linn. Sp. PI. 312. 

 Willd. Sp. PI. V. I. 1262. See Asclepias, n. i. Apo- 

 cynum africanum, lapathi folio ; Comm. Rar. 16. t. 16.) — 

 Leaves undulated, naked. Corolla bearded. — Native of 

 the Cape of Good Hope. Sent to Kew garden, in 1783, 

 by Mr. John Grsefer. This is a green-houfe plant, flow- 

 ering in July. Mr. Aiton marks it as ijhrub; but Com- 

 melin fays the thick, white, perennial root fends up every 

 year, in the early fpring, two or three thick, round, green, 

 iezfyjlems. All authors fpeak of the leaves as oppofite ; 

 but in our Linnxan fpecimen, gatliered at the Cape by 

 Thunberg, they are alternate, feffile, three or four i«iches 

 long, ovato-lanceolate, gradually tapering to a bluntiffi 

 point, with a thick mid-rib, and numerous interbranching 

 veins ; nearly fmooth on both fides ; undulated and rough- 

 i(h at the margin. Umbels axillary, italked, much fliorter 

 than the leaves, with hairy ilalks, and linear hairy brafleas. 

 Flowers green, their fegments denfely bearded at the extre- 

 mity, witli white fhaggy hairs. Follicles covered with 

 fpreading hairy filaments, an inch long. Every part of the 

 plant, when wounded, difcharges a copious milky fluid. 



2. X. grandiflorum. Large-flowered Xyfmalobium. 



I 



X Y S 



( Afclepias grandiflora ; Linn. Suppl. 170. Tliunb. Prodr. 

 47. Willd. Sp. PI. V. I. 1264. See Asclepias, n. 26.) — 

 Leaves llalked, hairy. Corolla fmooth. — Gathered by 

 Thunberg, at tlie Cape of Good Hope, but as yet a 

 ftranger to our gardens, nor does the Linnxan coUeftion 

 contain a fpecimen. The Jh-m is faid to be fimple, eredt, 

 and hairy. Flowers large, axillary, ftalked ; but, as far as 

 we can gather, the umbel is not elevated on a common 

 ftalk, as in the foregoing. Corolla fpeckled like Fritillaria 

 Meleagris, and of a fimilar colour. 



XYSTARCHA, in Antiquity, the matter or diredor 

 of the xyftus. 



In the Greek gymnafium, the xyftarcha was the fecond 

 officer : the firft was the gymnafiarch. The xyftarcha was 

 his lieutenant, and prefided over the two xyfti, and all ex- 

 ercifes of the athleta; therein. 



XYSTICI, among the Ancients, a defignation given to 

 the athletx, becaufe they performed their exercifes in the 

 xyftus. 



XYSTIS, in Ancient Geography, a town of Afia Minor, 

 in Caria. Steph. Byz. 



XYSTRIS, in Botany, Schreb. Gen. 138. Poiret in 

 Lamarck Dift. v. 8. 822, is one of thofe genera of pro- 

 feffor Schrebtr's, to which we have adverted under Wiie- 

 LERA, (f^e that article,) as being unintelligible to all but 

 thofe who maj have acoefs to the learned author's herba- 

 rium, or to fome 'eiord in his manufcripts. The name is 

 Greek, fiTiJif, a curry-comb, or fcraper. — Clafs and order, 

 Pentandria Monogynia. Nat. Ord. Epacrideie of Br^wn ? 



Gen. Ch. Cal. Perianth inferior, of one leaf, in five 

 deep, lanceolate, acute, fpreading, hifpid, permanent feg- 

 ments, each contrafted at the bafe. Cor. of one petal : 

 tube very (hort ; limb in five deep, ovate, obtufe, veiny, 

 fpreading fegments. Stam. Filaments five, briftle-fhaped, 

 ereft, fpreading at the fummit, fliorter than the corolla, in- 

 ferted into the middle of its tube; anthers oblong, ereft. 

 Pifl. Germen fuperior, globofe, pointed ; llyles two, ca- 

 pillary, ereft, combined in the lower part ; ftjgmas obtufe. 

 Peric. Drupa globofe, furrounded at the bafe by fhort, 

 proftrate hairs, inferted into the middle of the calyx. Seed. 

 Nut globofe, furrowed, of ten cells ; kernels oblong. 



Whether this genus be founded on fome New Holland 

 fpecimen of the natural order of Epacridej;, and whether 

 the rigid or prickly habit of the plant fuggefted the name, 

 can only be matter of vague conjefture. We acknowledge 

 that the divifion of xhejlyle, and the hifpid fegments of the 

 calyx, militate greatly againft our ideas of the fuppofed 

 natural order. In total darknefs, however, any glimmer- 

 ing of light is v/elcome, and we will therefore hazard 

 another conjefture, not altogether inconfillent with the 

 former. As Schreber places Xy/lris immediately after the 

 Jacquinia of Linnaeus, can it poffibly have been founded on 

 Jacquinia rufcifoUa, of whofe fruftification no botanift, as 

 yet, has given any fufficient account \ There feems an af- 

 fociation of ideas between the habit of Rufcus, and the 

 name of Xyjlris ; and the globofe pointed figure of theyVu;'/, 

 as copied from Plumier in Ddl. Hort. Elth. t. 123, anfwers 

 to part of the above defcription, though the permanent 

 calyx is drawn obtufe, and not apparently hifpid. 



XYSTUS, Hus-of, formed of |uii/, to polijh, or rub, in the 

 Ancient ArchiteBure, among the Greeks, was a long fpa- 

 eious portico, either open, or covered over ; in which the 

 athletae, and others, praftifed wreftling and running. 



The xyftus made a neceffary part of a gymnafium. The 

 athletx, who praftifed in it, were thence called xyjlici. 



XvsTL's, among the Romans, was an alley, or double 

 row of trees, meeting arbor-wife at top, and forming a 

 (hade to walk under. 



