The Botany of Gough Island.I. Phanerogams and Ferns
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THE BOTANYOF Goua~TSLAND.-I. Phanerogams and Periis. By R. N. RUDMOSEBROWN, B.Sc., Botaniat of the Scottish National Aiitarctic Expediticm. (Communicated b. Mi. W. BOTTINOHENSLET, F.H.S., F.L.S.) [Rrnd 4th Mar, 1!)05.] (1’IATES 7-9.) GorGii ISLAND,or Diego Alrarex, whic!i lies in the mid-South A tlautic (Lat. 4.0’ 20‘ S., Imig. 9’ 56’ 30” W.), may be regarded as tlie most outlying islillId of tlie TrisiiLri da Cunha group. It lics Y.E. by 8. about 220 iiiiles iioiii Kightingde Jsland, the ilearest island of the groril). It is a small island si.nie 7 or 8 mile3 in a northerly aiid soiitherlg direction and 3 or 4 miles east aud webt. It rises to a height of about 4000 feet. The idend has never beeii peririariently inhabited, though tlio islaiiders of Tristmi da Cunlla appear to lm\e occanionally visited it according to Mr. JI oseley *. From August 1888 to J-muary 1880 a party of twelve meir belonging to a Kew Londori sealing schooner lived there. One of these men (George Comer), who appears to have had pome lrnoxledge of scieiice, besides bringiug himc tome bird-skins and eggs, kept a diary in which are a few notes relating to platits. Cuirier ^t- says ‘‘ there are two kiiidd of trees, though while one is pl~~iitifiil,the other is quite scarce. The grass and brakes grow very rank.” “Wood is plentiful. The trees are stunted, but quite lliick in some places on the island.” “ The trees retaiii iheir leaves tile year round.” “ The thick bushes extend to ail elevation ot’ about 2000 feet.” The tree referred to is no doubt Phylica nitida, uliile pomib!y the other “ tree ’I is the tree-fern Loinnria Boryizna. Coiner also states that lie fuurid some putttoes growing wild where there uscd to be a cerrip of seulera 18 years ago.” Near the landing-place, on \:list is appareiicly the ody piece of level ground near aea-level, ruins of one or tLvo huts are to be seen. These, I alterwards Found at Cape Town, had been iuhabitad in the year 1892 by a party of sealers from South Africa who hid spent thirteen months on thc island. Tim eeirling had proved a coiiiparatire failure, aud they had uot * Mosrley, Journ. Linii. SOL,But. xi?. (1874) p. 384. t Vcrrlll, Trans. Curiii. dcsd. iu. (1895) lit. ii. 11. 432. TIIF: mr.Lxr OF CIOUGII rsr,.mD. 2.39 rcturried. SouLh-Sda whalers have occasionally touched here arid even brought back collections of birds aud rocks, but no plants seem to have b-en gathered. These whalers, chiefly dmericaqi, are no doubt responsible for several introduced plants on the islmd. All that was pre\-iously lruowa of the botany of' Gough Island mas the statement of the Tristan da Cunliaiis that Phylica grew there, slid that several of tlie other plnnts were similar to the Tristan species. The Scottish National Rritarctic Expedition, on its return from the Antarctic ltegions in April 1904, made a stay of thrcle daj s off this island ; but oiily 011 one (April 22iid) was it podde, owing to the high sea running, to effect a landing, and even on that day it was only accomplished with difficulty. The extremely bad aiichorage aid the squally nature of the wind made it iiiiperntivc: that the shore party should keep within easg reach in the everit of a suddeii recall being necessary. This was unfortunate, as it preveuted a visit to the higher ground, where several other species might have been found. On approacliiug the islatid one is struck by the amount of green to be seen: from the higheat summit to the water's edge it seems to be clothed with vegatatioii, aiid even the steepest precipices, iii which the lalid usually meets the sea, have their coveririg of moss. Rainfall is probably great, as evidenced in the cascades of water pouring over the cliffs on all sides. Comer * notes inces- sant strong gales with mist, raiu, and siiowiii the meteorological log he kcapt while on the island, but he apparently took very few readings of the air-temperature. Probably, however, the climate of Gough Islatid is very similar to that of Tristan da Cuuha, where the temperature varied from 48" F. in winter to 74" 17. in suininer, and the precipitstiori is excessive the whole year round. At the time of our viait there was ao snow-cap on the summit. On the eastern side of the island a torreut coming down to the sea has cut a deep glen, aiid this seems to afford the only practicable road to the iiiterior. It was here ttat a landiiig was effected+. On landing one notices the rankness of the vegetation. Above high-water docks (R~mex$*utescem)and the wild celery grow in * VerrJl, Trans. Coun. Acad. ix. (1895) pt. ii. p. 471. For i~ fuller account of Guugli Island, sce Scot. Gcog. khg. sx: (11)05) 1'. 4:jo. 24 0 Ylt. It. N. RUDNOSE BROWN OX luxuriant profusion, and in more stony ground I found several plmts of the sow-thistle (Sonchus oZerncrzis)--these latter in flower. The tussac-grass (Xpartina arundinacea) was not, at the plncc of landing, so abundant as in other parts of the coast, but here and there on the hillsides down to sen-level there were large tufts of it. In habit it is very similar to the tussac-grass of the Palliland Islands, but doe3 not appear to grow in such mawes as to almost etitirdy exclude other plants as it does on those islands. The only sward-forming " grass " seems to be Xcirpus (spp.) : on the southern aide of the stream vJas about half an acre of this, making a rich pasture. Other grasses are to be found, but growing in more isolated tufts. The characteristic tree of the Tristan da Cunha group (PhyEica nitida) iR \cell represented, and grows 011 Gough Island from about 2000 feet to ~ea-level,but above 100 feet it is most plentiful. The tree grows some 20 or 30 feet in height even on the most exposed ridges. The stems are not very thick, not more than 10 to 12 inches, and the branches are long and straggling, with leaves only at the extreme ends. Most of the branches are thickIy encrusted with lichens. Tree-ferns grow in the rich ground beside the stream, and reach a height of 4 feet or more. The beach is thickly strewn with water-worn stems of these ferns, which have probably been brought down by the stream when in spate, carried into the sea and washed up on to the beach. Several species of ferns grow in nooks and crannies of the nioist rocks, and apparently easily obtain a footiiig in the relatively soft volcanic ash. Mosses are plentiful everywhere, and in the bed of the stream 1 got several specimens of a liver- wort. The only plants in flower were Sonchus oleraceits and Apium austrule and two species of Rwnex, and the majority of even these were in seed. Gnaphrclium pyrmiiidnle bore n ithered flowers, and Phylica nitida and Empetrum niyrurn, wr. rubriiq were in fruit in a few places. I found no trace of any plants introduced for cultivation by the settlers whose ruitied huts we found. Beg ond the huts was half nn acre of gi ound beset with tree-stumps, the remains, no doubt, of the native tree which they had cut down fvr firewood. The plants of Gough Island have, as might he expected, proved to be very sitnilar to those of Tristan da Cullha. The present collection contains seveuteen species of phanerogams and ten of nm no’r INT OF OOUCIII TSTAS~. 2.41 ferns. Four of the seventeen species of phaiierogams arc almost l~itlioutdoubt introdluced (IQpochPris glnbm, Sonchus olwnceus, Ruwx ohtirsifolius, aid 2’lnnta.yo nzajor). Of the remaining 21 specie+ of Gough Island planta, eighteen avrecorded from Tristnn da Crinha-one (I[ydrocofyle lnrcoc~phala)is a Soutli- Anieiicaii plant and two are endemic (Cotula sp. nov. and Asplenium sp. nov.). Of the eighteen species also recorded frotn Tristan da Cunha, four certainly, and probably six, are endemic to the group. The mosses, I;verworts, lichen@, and fungi, the determination of which is not quite complete, will form the subject of a second paper. In co~rcluuion,I have to thank the authorities at Kew and the British Museum for the f~iciliticsgranted me for working in their herbaria. To Mr. C. B. Clnrlre I am particularly iiidvbted for his determination of tlie species of Seirpzis, and I nould express my th:tnIrs to Mi,. A. N. Bruee, B.Sc., for the care aud trouble he has talreu in the drawing of Plate 9 accompanying this paper. DICOTYLEDONES. PHYLICANITIDA, Lam. Encycl. ii. p. 77; BC. I’roclr. ii. p. 36 ; Hemsl. Cha11. Bot. i. 11. p. 148, t. 25. P. arborea, Thozt. Esg. 31. Trist. p. 45. P. inuuritiaisa, Boj. es Buker, 31. Xciurit. p. 63. Very common on the island up to a height of about 2000 feet, growing even on the nrost exposed ridges. It seldom grows more than some 25 feet in height, aid the stems are aln ays much bent and gnarled and generally covered rith a growth of licbens. Distribution. Tristan da Cuiiha, Iiiaccessible and Nightingale Islands, Amsterdam Island, lteuniou and Mauritius. HTDROCOTTLELEUCOCEPHALA, Cham. et cSchlecRt. in Limcen, i. (1826) p. 364. Common in the glen in 8%ampy places under waterfalls. This species differs from Hydrocotyle cnpitcrta, Thounrs-the Tristan da Cunha plant-in the ahost total abseiice of hair3 011 the leaves and leaf-stalks, except an occasional sparse covering nrar the blade.