Wall. — Ranunculus paucifdlius T. Kirk. 95 



Lepidium sisymhrioides make spots ot very dull cliocolate, which are con- 

 fused in the general scheme with the paler browns, dull greenish-yellows, and 

 greys, of Oreomyrrhis andicola, Myosotis decora, Anisotome Enysii, &c. The 

 sparsely scattered plants of Ranunculus paucifolius become almost invisible 

 in this environment, and play no leading part in determining the appearance 

 of the whole unit. The whole effect is most peculiar ; the calciphile flora 

 gives the impression that it belongs elsewhere — to another age, another 

 climate and country. Much the same effect is produced, in my experience, 

 by the isolated patches of ancient fen vegetation which survive at such spots 

 as Wicken and Cottenham, set like savage aliens of some older and vanishing 

 race in the midst of the green crops and pastures of modern Cambridgeshire. 



(c.) As the formation becomes more nearly closed, on the borders of 

 the grassy closed areas, Plantago spathulata appears in great quantities, 

 and the' closed formation of the immediate neighbourhood includes Festuca 

 7iovae-zelandiae, two or three others of the usual grasses of the district, 

 Raoulia subsericea, Hydrocotyle novae-zelandiae var. montana, Vittadinia 

 nustralis, and a fair amount of moss. Here occasional plants of Lepidium 

 sisymhrioides appear, but not far from the pure limestone patches. 



((?.) The chief introduced plants which occur in the basin are Arenaria 

 serpyllifolia. (extremely abundant everywhere^more so than any native 

 plant), Cerastium glomeratum, Hypochaeris radicata, the large ox-eye daisy 

 (which completely covers the slopes on the eastern side of the rocks out- 

 side the basin), and Verhascum Thapsus. It is not without significance, 

 as showing the very special and peculiar character of the locality, that 

 Hypochaeris radicata, elsewhere so exceedingly abundaiit in New Zealand, 

 is here comparatively rare. 



It must-be added that the rocks above the basin and the steepest slopes 

 around them also harbour Epilohium gracilipes (which never occurs on the 

 flat), Senecio Haastii (which is comparatively seldom seen below), Senecio 

 lautus var. montanus, and a good number of such shrubs as Coprosma 

 propinqua, Discaria toumatou, and Aristotelia fruticosa. Upon these shrubs 

 the peculiar parasite Korthalsella clavata is found ; this also grows upon 

 shrubs in other limestone rocks {e.g., those at the junction of the Porter and 

 Broken Rivers), but apparently is found only in the Castle Hill district. 



A certain number of these plants are definitely calciphiles, and occur 

 in no other situations ; others seem to grow by preference on limestone, 

 but are not confined strictly to it (in this district, at any rate) ; and the 

 rest are of general distribution. 



In the first class are Ranunculus paucifolius, Poa acicularifolia, Korthal- 

 sella clavata, Epilohium gracilipes, Myosotis decora, Anisotome Enysii. In 

 the second are Oreomyrrhis andicola var. rigida and Crepis novae-zelandiae. 



Several of them exhibit marked xerophytic characters, as described by 

 Cockayne and Laing (Speight, Cockayne, and Laing, 1911, p. 358), and 

 among these Ranunculus paucifolius is conspicuous. It has the pale ashen- 

 purple colouring which distinguishes the shingle-slip plants generally, such 

 as its relations Ranunculus chordorhizos, R. crithmifolius, and R. Haastii. 

 Lepidium sisymhrioides has special adaptations, of which the disproportion- 

 ately long root is most remarkable (Cheeseman, p. 42). Anisotome Enysii 

 shows a colouring very similar to that of Ranunculus paucifolius. There is 

 here a marked degree of epharmonic convergence. 



These plants make up a community of intense interest, and the problem 

 of their existence is bound up with that of Ranunculus paucifolius, whose 

 limited distribution and feeble powers of reproduction help to put that 

 problem in a clearer and more striking light. 



