Urtica perconfusa Grosse-Veldmann & Weigend, 2016

Grosse-Veldmann, Bernadette & Weigend, Maximilian, 2016, Weeding the nettles IV: A redefinition of Urtica incisa and allies in New Zealand and Australia, including the segregation of two new species Urtica sykesii and U. perconfusa, Phytotaxa 245 (4), pp. 251-261 : 257-258

3. Urtica perconfusa Grosse-Veldmann & Weigend , spec. nov.

Type:— NEW ZEALAND. [Greater Wellington (North Island): Wellington Land Distr.] Wellington, Waiwiri Stream, at bases of Carex secta amongst Phormium swamp, Alt: 1, Map 260: S 25 Grid: 934619, Lat: 40° 37’ S, Long: 175° 10’ E, P. J. De Lange 2094 (holotype: CHR 497596!).

Lax, slender, perennial, rhizomatous herb 0.45–2.0 m, usually much-branched, scrambling or climbing. Stem indumentum of few stinging hairs with pluricellular base c. 0.2–0.5 mm overall and erect setae 0.2–0.4 mm long and few simple trichomes 0.2–0.3 mm long. Leaf lamina 40–80(–100) × 4–10 mm narrowly ovate; surface sparsely pubescent with short simple trichomes 0.2–0.5 mm long and few stinging hairs (abaxially only on the veins), adaxially with punctiform cystoliths; leaf base rounded; margins regularly dentate, rarely doubly dentate, with 12–20 teeth on each side; leaf apex acuminate; lamina thinly membranaceous; stipules free (4 per node) 2–4 mm long; petioles thin, flexuose, 15–45 mm long. Plants monoecious. Staminate flowers with tepals c. 1.3–1.8 mm long. Pistillate flowers with short tepals 0.5–0.8 mm long and long tepals 0.8–1.2 mm long, sparsely pubescent, esetulose. Inflorescence glomerulous, 3–10 mm long, usually shorter than petioles. Mature fruit with longer tepals 1.2–1.5 mm long, achenes subcircular in outline, rounded at base and at the tip, laterally flattened, c. 1.2–1.5(–2.0) × 0.8–1.3 mm.

Additional specimens examined:— NEW ZEALAND. Without locality data, Jung 226 ( SP 023898 !) ; without locality data, W. Colenso s.n. ( SP 023899 ) ; Greater Wellington (North Island): Wellington Land Distr. , Ranigtikei , Turakina , Makirikiri Stream catchment, “Tunnel Hill Farm”, S 40° 04’, E 175° 12.2’, 05 Mar. 1995, C. C. Ogle 2926 ( CHR 506008 !) ; same locality, Lake Horowhenua, Hokio Stream , S 40° 36’, E 175° 14.2’, P. J. De Lange 2141 ( CHR 497643 !) ; Marlborough (South Island): Marlborough Land Distr., Opawa River , Blenheim , 5 m, rough pasture and river banks, 30 July 2000, J. Clayton-Greene CJ01:14 ( CHR 525620 !) ; North Canterbury (South Island): Canterbury Land Distr. , Low Plains , Amberley Beach , S 43° 09’, E 172° 47’, 28 July 1999, R. Pender s.n. ( CHR 536516 !) ; Canterbury Plains , “common”, Oct. 1872, J. von Haast s.n. (FI!, FR!) ; Hannover plains , J. von Haast s.n. (FR!) .

Notes:— Urtica perconfusa Grosse-Veldmann & Weigend corresponds to Urtica linearifolia (Hook.f.) Cockayne sensu Cockayne (1915) . It has been mistakenly identified as U. incisa subsp. linearifolia (see discussion under U. incisa ) in the past ( Cheeseman 1906, 1925, Allan 1961). It is very surprising that this confusion has persisted, given that the type of this New Zealand endemic was from Tasmania! Urtica perconfusa Grosse-Veldmann & Weigend is a lax, much-branched, scrambling or climbing species up to 2 m high; the inflorescences are glomerulous and very short, usually much shorter than the petioles, sometimes with both sexes mixed on the same branch or at least always with inflorescences of both sexes on the same plant; leaf morphology does resemble that of the narrow-leaved form of U. incisa , but the leaves of Urtica perconfusa are narrowly ovate with a rounded base, thinly membranaceous and with thin, flexuose petioles. Urtica perconfusa is densely and shortly rhizomatous, very similar to U. sykesii (see Tab. 1 for comparison).

Distribution:— Urtica perconfusa Grosse-Veldmann & Weigend is known from both the North and South Island of New Zealand, but apparently rare. It has not been reported from Australia and was considered as endemic to NZ already in its previous incarnation as “ U. linearifolia ” (but then with a type from Tasmania— Allan 1961).

Habitat and ecology:— Urtica perconfusa Grosse-Veldmann & Weigend is found in lowland swamps and along lake and river margins, often growing over old tree stumps and shrubs.

Phenology:— Urtica perconfusa Grosse-Veldmann & Weigend flowers throughout the year.

Etymology:— Urtica perconfusa Grosse-Veldmann & Weigend means “the thoroughly confused nettle” and commemorates its taxonomic history.

Conservation status:— According to the New Zealand Threat Classification System ( de Lange et al. 2013), Urtica perconfusa is considered “At Risk—declining” (factsheet NZPCN_Species_211.pdf downloaded from www. nzpcn.org.nz on 30 Nov. 2015).