REPORT ON THE BOTANY OF TIIE ATLANTIC ISLANDS. 83 



MONOCOTYLEDONES. 



LEMNACE^E. 

 Lemna minor, Linn. 



Lemna minor, Linn., Sp. PL, ed. 1, p. 970; Hegelm., Monogr., p. 142, tt. 9 et 10. 

 " Lemna polyrrhisa, Linn.;" Melliss, St Hel., p. 330? 



St Helena. — Introduced ? Very common aud abundant in the mountain streams, 

 and covers every pond of water — Melliss. 



The only specimens of a Lemna that we have seen from St Helena are Lemna minor, 

 collected by Melliss himself, hence we suspect that these and the Lemna polyrrhiza of his 

 enumeration are the same, though, of course, it is possible that both species occur. This 

 very widely diffused aquatic was probably accidentally introduced into the island, though 

 even in Burch ell's time it was abundant, as we learn from his notes ; yet he does not appear 

 to have collected it. Roxburgh includes no Lemna in his catalogue, but as he visited the 

 island after Burchell it can only be regarded as an omission. Hegelmaier, however, the 

 monographer of the order, has no record of any member of the order occurring in this or 

 any remote islet in any part of the world. 



Water-plants sometimes spread very rapidly when introduced into a fresh region. Of 

 this we have an example in this country in the American water-weed, Elodea canadensis. 

 Yet we should not have expected that a Lemna would ascend the mountain streams. One 

 species occurs in the Bermudas, whither it may have been carried by some water-bird. 



JUNCACE^E. 

 Juncus bufonius, Linn. 



Juncus bufonius, Linn., Sp. PI., ed. 1, p. 328; Kunth, Enum., iii. p. 353; Melliss, St Hel., p. 342. 



St Helena. — Introduced? Upland places at 1000 feet altitude, apparently native — 

 Hooker ; in moist shady places — Burchell ; very common on the high land — Melliss. 



Common in nearly all temperate regions. 



Juncus lomatophyllus, Spreng. 



Juncus lomatophyttus, Spreng., Neue Entdeck, 1821, ii. p. 108 ; Buchenau, Monogr. June. Cap., p. 46G. 

 Juncus capensis, Thunb., var. latifolius, E. Mey., June, p. 48, ex Kunth, Enum., iii. p. 342. 



St Helena. — Indigenous 1 From the valley by Miss Mason's — Burchell, 97. 



This very distinct species is common in South Africa, and was most likely introduced 

 into the island ; yet Burchell seems to have regarded it as indigenous. In his manuscript 

 notes he gives the general habitat thus: "In rivulis regionis interioris"; and Melliss 

 says it is very common along banks of streams throughout the island. 



