Flora of New Zealand Series

R. limo-selloides F. Muell. ex Hook. f. Ic. Pl. 1867, t. 1081 non Turcz. in Bull. Soc. Nat. Mosc. 27, 1854, 11, 276.

Original localities: "In the Whangape, Waikare, and Waiti Lakes, Waikato, T.K"

Small slender glab. herb with filiform creeping stems, rooting at nodes, internodes us. very short. Lvs solitary or few together at nodes, on filiform petioles up to 3 cm. long; lamina up to 1cm. long, slightly dilated to ± spathulate. Peduncles filiform, 1-2 cm. long. Fls ± 5 mm. diam.; sepals 4, ovate to oblong, ± 2 mm. long; petals 4, yellow to purple, linear, ± 6 mm. long, revolute; gland 1 well above base. Fruiting heads ± 2 mm. diam.; achenes small, few, ± turgid, obliquely ovoid; style slender, recurved.

DIST.: N., S. Lowland to upper montane on margins of swamps and lakes or streamsides, local from lat. 37° 30' to 45° 30'.

FL. 11-4. FT. 11-4.

POLYMORPHY

Our knowledge of the N.Z. Ranunculi is very defective and no satisfactory treatment is as yet possible. It is clear that genetic differences, habitat modifications and hybridism all play a part in the great diversity shown by many spp. and linking forms, e.g. R. clivalis, R. enysii, R. rivularis. Allan (J. Ecol, 14, 1926, 75-76) showed how on one mountain several different forms of R. monroi occurred and that these were related to the different habitats occupied. By transplant studies on the mountain he found that a small densely hairy plant could be changed into a tall almost completely glab. one. Simpson (T.R.S.N.Z. 75, 1945, 187) grew small plants of R. rivularis, of semi-stagnant swamp, without stolons, or rhizomes, but with a corm-like stock; these developed in "the usual manner", i.e. increased in size and developed long rhizomes, in cultivation.

Wall (Rec. Canterbury Mus. 3, 1926, 51) described and illustrated a single wild plant transferred to a garden, as of the probable origin R. chordorhizos × monroi var. dentatus. Cockayne and Allan (Ann. Bot., Lond. 48, 1934, 21) listed, with good field evidence, as hybrids: R. matthewsii Cheesem. in Man. N.Z. Fl. 1906, 1133 (R. buchananii × lyallii) and R. baughanii Petrie in T.N.Z.I. 45, 1913, 265 (R. sericophyllus × var. simpsonii). Allan (Genetica 8, 1926, 634) on specimens and field evidence collected by the late G. Simpson and J. Scott Thomson, illustrated hybrids of the origin R. buchananii × haastii var. scott-thomsonii and R. buchananii × lyallii. Cockayne and Allan (loc. cit.) mentioned several hybrid groups, including the well-attested R. buchananii × sericophyllus var. simpsonii, sericophyllus × var. simpsonii, and other possible groups needing further study.

W. B. Brockie has raised several hybrids from plants brought into cultivation, e.g., a handsome sterile hybrid with creamy flowers, between R. lyallii and R. insignis. F. J. F. Fisher has made extensive field studies amongst the alpine spp. and has raised numerous hybrids.