15G THE VOYAGE OF H.M.S. CHALLENGER 



Milne have culms nearly as slender as those of the present variety, though none is quite 

 so slender. Independently of the extreme slenderness of Scirpus moseleyanus, it is also 

 easily recognised by its deep red-brown leaf-sheaths. Whether this character be accidental 

 or not cannot be proved from the one gathering before us, but specimens from both islands 

 exhibit the same character. In one tuft, however, from Nightingale Island, which is pro- 

 liferous, the colour has either flown or never was so prominent. The very small, some- 

 times almost obsolete, leaf-blade is much the same in both forms, as are also the glumes, 

 the outer ones being remarkable for the very much thickened keel, which is prolonged 

 into a stout mucro. The analysis of the flowers of the Isolepis prolifera of the Flora 

 Tasmanica, ii. t. 144, also offers many points of resemblance ; the glumes especially are 

 almost exactly the same, those of our plant having similar red lines as well as the 

 thickened keel. The flowers of Scirpus moseleyanus, of the plant figured, which we 

 examined, were either monandrous or diandrous, and we met with one bifid style. This 

 plant was collected in Inaccessible Island. Among the specimens collected in Nightingale 

 Island were some of shorter, stouter growth, bearing more highly developed spikelets, in 

 which nearly all the flowers examined were triandrous. Eipe nuts were not found. 



Scirpus thouarsianus, Schult. 



Scirpus thouarsianus, Schult. in Eoem. et Schult. Syst. Veg., ii. Mant., p. 84. 



Scirpus prolifer, Thouars, Esquisse El. Trist., p. 36, t. 7, figura sinistra, non Eottb. 



Isolepis prolifera, Carmich. in Trans. Linn. Soc. Loud., xii. p. 503. 



Isolepis thouarsii, Dietr., Sp. PL, ii. p. 109; Kunth, Enuni., ii. p. 216. 



Scirpus sguarrosus, Spreng., Syst. Veg., cur. post., p. 28. 



Isolepis acugnana, Schult. in Kcem. et Schult. Syst. Veg., iii. Mant., p. 532. 



Isolepis squarrosa, Carmich. in Trans. Linn. Soc. LonJ., xii. p. 503. 



Scirpus prolifei-o-ramosus, Bceckeler in Flora, 1875, p. 261. 



Tristan da Cunha. — Endemic. TJiouars; Carmichael; Moseley. 



We have not seen Thouars' type, and from his brief description and imperfect figure 

 we cannot determine with certainty what particular form he had in view ; but from his 

 remarks on the distribution of the species, we assume that he considered all the forms 

 known to him in the islands, except that which he described as Scirpus sidcatus, as one 

 species. His words are : " This plant grows everywhere, in the dryest parts of the 

 mountains, forming a short turf of a beautiful green." His figure agrees best with a small 

 piece of the form which Bceckeler has designated Scirpus prolifero-ramosus. This was 

 collected by Mr Moseley, both on the Main Island and on Inaccessible Island. 



Scirpus thouarsianus, Schult., va'r. hicolor, Hemsl. (Plate XXXIV. B., figs. 8-1 G). 

 Scirpus thouarsianus, Schult., var. bicolor, Hemsl. 

 Scirpus bicolor, Spreng., Syst. Veg., cur. post, p. 28 (species). 

 Isolepis bicolor, Carmich. in Trans. Linn. Soc. Loml, xii. p. 503 ; Ivunth, Enum., ii. p. 216. 



Tristan da Cunha. — Endemic. Carmichael; Milne and Macgillivray ; Moseley. 



