198 Transactions. 



identical with one which is extremely common on Arthur's Pass, and in 

 Westland generally from Mount Alexander to, at any rate, the neighbour- 

 hood of the Franz Josef G-lacier. This plant was included by Cheeseman 

 (Manual, p. 549) in his conception of 0. macrocarjxi Hook, f., while in the 

 herbarium of T. Kirk it is also so designated. But the plant on which 

 0. niacrocarpa was founded by Hooker was collected by Lyall at Chalky 

 Bay, and, according to the original description in the " Flora Novae- 

 Zelandiae," p. 198, the leaves are cordate at the base. In his description 

 of the same specimens in the " Handbook of the New Zealand Flora," 

 p. 218, Hooker, strange to say, makes no reference to these cordate leaves, 

 so that without hesitation all New Zealand botanists who visited Arthur's 

 Pass referred the large Ourisia of that locality to 0. macrocarpa, and thus it 

 came to be looked upon as typical. In 1912 I visited the Clinton Saddle, 

 and, to my surprise, found that the large Ourisia of that locality differed in 

 certain particulars from the Arthur's Pass plant, and answered perfectly to 

 Hooker's description of 0. macrocarpa in the " Flora Novae-Zelandiae." 



The chief differences between the two plants are as follows : — 



(1.) Leaf-lamina : 0. macrocarpa — Frequently rotund with cordate base • 

 in small specimens broadly ovate with cordate, subcordate, or occasionally 

 rounded but never cuneate base. 0. calycina {i.e., Arthur's Pass, &c., 

 plant) — Ovate or ovate-oblong, with more or less cuneate base, and never 

 orbicular with cordate base. 



(2.) Petiole : 0. macrocarpa — Rareh' more than 4 mm. broad, and fre- 

 quently less, more than twice as long as the lamina, almost glabrous. 

 0. calycina— 11 mm. broad or more, hardly as long as the lamina, margined 

 with close white hairs which extend to base of lamina on margin. 



(3.) Crenations : 0. macrocarpa — Large, 5 mm. at base, rounded, con- 

 tinued to leaf-sinus at base of leaf. 0. calycina — Much smaller, 2 mm. 

 at base, obtuse or almost subacute, wanting on marginal portion of lamina. 



(4.) Bracts : 0. macrocarpa — Small, the largest about 3 cm. long by 

 .1-5 cm. broad, the uppermost in many -leaved whorls. 0. calycina — Large, 

 frequently 5 cm. long by 2-5 cm. broad, the uppermost in whorls of 2 to 4 

 leaves. 



(5.) Peduncle : 0. macrocarpa — Comparatively slender, only about 

 3 mm. diameter. 0. calycina — Comparatively stout, 5 mm. diameter or 

 more. 



(6.) Calyx-lobes : 0. macrocarpa — 6 mm. long, entire, obtuse, thick, 

 veins not evident. 0. calycina — 1-9 cm. long, crenate-dentate above, sub- 

 acute, thin, 3-veined and reticulating above. 



The above clear distinctions show that we are concerned with two 

 distinct plants, which, as they extend virtually unchanged over wide areas, 

 are true-breeding races. Some may prefer to consider them distinct species, 

 while others will group them together, on account of their close relationship, 

 as an aggregate species under the name of 0. macrocarpa. Possibly, from 

 the phytogeographical standpoint this course should be adopted. There- 

 fore I propose the name 0. macrocarpa Hook. f. var. calycina (Colenso) 

 comb. nov. for the Westland plant which equals 0. calycina Col., and for 

 the plant of south-west Otago 0. macrocarpa var. cordata var. nov. The 

 latter equals the species 0. macrocarpa of Hooker in the " Flora Novae- 

 Zelandiae," vol. 1, p. 198, so no further description is needed here. Perhaps 

 a more searching comparison of the flowers of the two varieties may reveal 

 other constant differences, but those cited above are ample to show the dis- 

 tinctness of the two plants. 



