486 ORCHIDS 



Tetranv'cra. 

 species usualh- i^-rriwn — T. bicolor [Bciith.) and 7'. rigida — are 

 best known in gardens under the name of Lcptotcs. Tlie\' 

 require cool intermediate-house treatment, with cultural 

 conditions as for Soplirojiitis. 



T. rig-ida [Liin//.). — A rigid species witli cylindrical, linear, 

 channelled, acuminate, recurved foliage. Sepals and petals greenish ; 

 lip rosy, purple-striped, exserted, the lateral segments spreading, 

 the middle one roundish-obovate, large ; scape distantly sheathed, 

 few-branched above or simple. The flowers are borne in Spring. 

 Introduced from the \\'est Indies. Syn. BraisiTvula e!t\i;aus. 

 (B. M., t. 309S.) 



THELYMITRA. 



Twent)- sjjecies of greenhouse, terrestrial Orchids are 

 included in the genus Tlielyniiti'a {Forst.). It belongs 

 to the tribe Ncottuw. Forster's name is from theirs, a 

 woman, and niiti-a, a cap ; in reference to the hood-shaped 

 column. The S}jecies are nati\-es of Australia, Xew 

 Zealand, and the i\Iala}-an Archipelago. They require the 

 same cultural conditions as Bleiia. T. grandiflora {Fitrjg.) 

 is the species sometimes found under cultivation. 



THRIX5PERMUM {luui?:). A synonym of Sarcochilus. 



THUNIA. 



In the " Genera Plantarum," this genus, ^\'hich is nearh' 

 allied to Pliaius, is included therein. It differs so much, 

 ho\ve\-er, from Phaiits proper in stem, leaf and inflo- 

 rescence, and is now so generall)' known under the abo\-e 

 title, that \\'c preter to retain it as a good garden genus, 

 thereby following the classification of the late Professor 

 Reichenbach. The name is commemorative of Count von 

 Thun Hohenstein. There are probably only two species 

 introduced, although specific names have been given to 

 what are simply varieties of these. The stems are erect, 

 terete, rather herbaceous, of only annual duration, the old 

 stem perishing as the new one develops ; they are clothed 

 with leaves to the base, these falling awa)' in autumn. 

 The flowers are produced from the apex of the young 



