202 Transactions. 



the edge of forest, or beneath large plants of Linum monogynum, show a 

 complete or almost complete absence of the purple colouring-matter in the 

 glandular hairs, and also tend to be larger, to have a much longer petiole 

 than usual, and to be less thickly covered with silky hairs or bristles (as 

 the case may be) than the usual form. 



5. Though the plant of S. saxifragoides is probably on the average a 

 little larger than that of S. lagopus, the difference is not great. Kirk's 

 measurements do not agree with the others. A leaf of S. lagopus 8 in. long 

 without the petiole would be most exceptional, but leaves 6 in. long with a 

 petiole of from 3 in. to 4 in. are common — e.g., on Mount Herbert — and 

 S. saxifragoides can hardly ever be much larger than this, though its leaves 

 are generally broader and more substantial. I have a very strong impres- 

 sion, which I hope to verify by future observation, that the plants of 

 S. lagopus in the neighbourhood of Akaroa Harbour are in general distinctly 

 smaller than those of the Mount Sinclair to Mount Herbert area. This 

 would explain the small measurements of Raoul's type. Some of the large 

 individuals of the Mount Herbert area, indeed, almost seem to be inter- 

 mediate states such as Hooker speaks of. The largest leaf of S. lagopus 

 measured by me shows the following dimensions : Length of blade, 6 in. ; 

 length of petiole, 3 in. ; breadth of blade, 4 in. This plant grew on the 

 south-western peak of Mount Herbert, and was exceptionally large. Its 

 measurements equal those of S. saxifragoides in any authority and exceed 

 most of them. A most exceptionally large plant of S. saxifragoides, how- 

 ever, gave the following 'measurements : Length of blade, 1\ in. ; length 

 of petiole, 4J in. ; breadth of blade, 6f in. This is much above the average 

 of the species, the plant being shaded by plants of Linum monogynum and 

 tussock-grass. 



6. Thus the leaf of typical S. lagopus is found to bear six different types 

 of structure — (a) The thick brownish " wool " of the rootstock, which covers 

 the base of the petiole and seems to pass gradually into (b) long white silky 

 hairs, which clothe the petiole and are continued up into the sinus and on 

 to the lower portion of the leaf ; (c) the characteristic stout bristle Which 

 occurs, as described below, on the margin and upon the upper part of the 

 blade especially ; (d) the dark-red or purple bristle which is thickly inter- 

 mixed with the white hairs upon the petiole, from the point where the 

 brownish " wool " passes into white hairs up to the apex, or nearly, on 

 the back of the midrib ; (e) the glandular marginal purple protuberances ; 

 (/) the white tomentum upon the back of the leaf. 



7. Many plants of S. lagopus bear the silky hairs as well as the charac- 

 teristic stout bristles. The silky hairs usually occur very thickly on the 

 petiole and at the base of the leaf and in the immediate vicinity of the 

 midrib ; less thickly, if at all, on the rest of the leaf, as depicted in Raoul's 

 plate. 



8. Many plants of S. saxifragoides bear the stout bristles which have 

 been hitherto considered to be characteristic of S. lagopus and S. belli- 

 dioides. The bristles occur in S. saxifragoides under these conditions :— 



(a.) They occur near the apex of the leaf upon the upper surface of 

 about one-fourth or one-third of the whole — not near the base, 

 and but rarely on the lower half of the leaf at all (as in Raoul's 

 plate of S. lagopus), though specimens have been observed with 

 the bristles fairly evenly distributed over the whole surface. (See 

 Plate XII.) 



(b.) They occur regularly and as a permanent character all round the 

 margin exactly as in S. lagopus and S. bellidioides. 



