Flora of New Zealand Series

R. cissoides auct. non  A. Cunn.

R. cissoides var. pauperatus Kirk Stud. Fl. 1899, 126.

Liane with slender to stout stems up to 10 m. or more tall; branchlets slender, unarmed to prickly; in open often of bushy growth with densely interlacing branchlets; prickles yellow, hardly recurved to straight. Lvs quinate to ternate, with prickly petioles and petiolules, stipules narrow-linear; lamina glab., polymorphic: (a) reduced almost to midrib, c. 1-5 cm. × 1-5 mm., often lobed at base, on petioles and petiolules up to 2 dm. long, us. beset with prickles; found on bushy form or on plants scrambling over low shrubs; passing into (b) well-developed lanceolate to ovate-lanceolate, distantly serrate to crenate-serrate, sts lobed, rounded at base, up to 7 × 3 cm., petioles and petiolules shorter, unarmed to markedly prickly; midrib unarmed or sparingly prickly. Fls in panicles or racemes up to 2 dm. long, pedicels pubescent; sepals oblong-ovate, pubescent, c. 3-4 mm. long; petals 5, yellowish, linear-oblong, c. 4-5 mm. long; stamens ∞; carpels ∞; frs c. 6 mm. long, flesh orange-red.

DIST.: N., S., St. Lowland to lower montane forest and forest outskirts.

HYBRIDISM

Various "intermediate" forms have led to the suspicion that hybrids occur, e.g. between R. australis and R. squarrosus, R. schmidelioides and var. subpauperatus, but convincing evidence is lacking. More certainly established are (a) R. cissoides × parvus, (b) R. parvus × schmidelioides : (a) Specimens of a single plant collected near Lake Brunner, Westland, by S. D. Barker in 1898 were described as R. barkeri Ckn. in T.N.Z.I. 33, 1900, 293; prostrate, branches unarmed or nearly so, rooting; lvs trifoliolate to unifoliolate, lamina lanceolate, serrate. Cultivated from cuttings no plants flowered till 1916, and since then flowering has been infrequent. It is now recognized as of hybrid origin and appears to be quite sterile. It is much grown in gardens for its habit and lustrous bronzy to purple lflts. A similar plant was found by W. McKay near Greymouth, but of more bushy habit and more freely flowering. Since then a few similar plants have been found. (b) Plants of the suggested origin R. parvus × schmidelioides have been found wild. Six hybrid plants were raised (Allan in T.N.Z.I. 58, 1927, 51 and 59, 1928, 643) using R. parvus as the pistillate and R. schmidelioides as the staminate parent. The progeny were all alike, passing through a unifoliolate seedling stage to a trifoliolate stage, the lflts lanceolate, acuminate, much resembling those of R. parvus but serrate. Flowering has been rare, the fls abortive with various abnormalities.

FL. 9-11. FT. 11-4.

POLYMORPHY

Regarded as compound spp. the N.Z. Rubi are fairly clearly separable as above, but there are ∞ forms tending to show an intergrading series. The causes are several: (1) all the spp., except perhaps R. parvus, show heteroblastic development from a unifoliate seedling, but the life-history of no sp. has been worked out; the juvenile of R. australis has been described above. The other spp. show narrow-lvd forms in the non-flowering state, but how far these forms are "juveniles" and how far they may represent distinct vars is uncertain; (2) all spp. show considerable epharmonic response to environment, e.g. in habit, in lamina and prickle development, in retarded flowering, but studies have been observational only; for a discussion see Cockayne in Amer. J. Bot. 20, 1933, 545, and Simpson and Thomson in T.R.S.N.Z. 70, 1940, 27. There is some evidence that certain spp., R. australis and R. cissoides especially, may be compound, i.e. with several true-breeding vars.