160 THE VOYAGE OF H.M.S. CHALLENGER. 



Uncinia brevicaulis, var. gracilior, Henisl. (Plate XLVI.) 



Uncinia brevicaulis, var. gracilior, Hemsl. 



Uncinia gracilis, Thouars, Esquisse Fl. Trist., p. 35, t. 5 (excl. synon.) ; C. B. Clarke in Journ. Linn. 

 Soc. Lond., xx. p. 400, partim. 



Tristan da Cunha. MacGilUvray and Milne ; Thouars. 



This variety has only been collected in Tristan da Cunha, and presents no marked 

 differences beyond greater slenderness. 



GRAMINE^E. 1 



Spartina arundinacea, Carmicli. (Plate XXXV.) 



Spartina arundinacea, Cannich. in Trans. Linn. Soc. Lond., xii. p. 504 ; Kunth, Enum., i. p. 279 ; 



Reichardt in Verhandl. k. k. zool.-bot. Gesellsch. "Wien, xxi. p. 31. 

 Ponceletia arundinacea, Thouars, Esquisse Fl. Trist., p. 36. 



Tristan da Cunha. Thouars; Carmichael ; MacGilUvray and Milne; Moseley. 

 Inaccessible and Nightingale Islands. Moseley. 



Also in the islands of St Paul and Amsterdam. 



This robust reed-like grass constitutes one of the main features of the vegetation of the 

 islands, and grows in such dense thickets as to be almost impenetrable in places. 



Agrostis ramulosa, Carmich. (Plate XXXVI.) 



Agrostis ramulosa, Carmich. in Trans. Linn. Soc. Lond., xii. p. 504; Steud., Synop. Glum., i. p. 175. 

 Agrostis carmiekaeli, Schultes in Ecem. et Schult. Syst. Veg., ii. Mant., p. 571. 

 Sjwrobolus? carmichaeli, Kunth, Gram., i. p. 68, et Enum., i. p. 216. 

 VUfa carmicJiaeti, Steud., Komencl. Bot. 



Tristan da Cunha. — Endemic. Carmichael; MacGilUvray. 



According to Carmichael, this grass and Agrostis media grow on the high part of the 

 mountain, forming the chief part of its herbage. A few straggling tufts were met with on 

 the low ground, along the bottom of the ravines, where the seeds had been washed down 

 1 1)' the torrents. It is not in the more recent collections that we have seen. 



Although the awn on the flowering glume is reduced to a mere rudiment, this is no 

 justification for removing it from the genus Agrostis; moreover, it cannot be regarded as 

 other than a congener of Agrostis media. 



Agrostis media, Carmich. (Plate XXX VII.) 



Agroeiis media, Carmich. in Trans. Linn. Soc. Lond., xii. p. 504; Koem. et Schult., Syst. Veg., ii. 

 Mant., p. 571 ; Kunth, Enum., i. [k 226. 



TRISTAN da Cunha. — Endemic. Carmichael; Milne; Moseley. 



i val introduced grasses have now become common ; they are mentioned in the introductory notes 

 preceding this enumeration. 



