Nomenclature
Scientific Name:
Salix repens L., Sp. Pl. 1020 (1753)
Synonymy:
Lectotype (chosen by B. Jonsell and C.E. Jarvis, Nordic J. Bot. 14: 152, 1994): Sweden, LINN 1158.71, image seen.
Vernacular Name(s):
arctic creeping willow; creeping willow
 Description

Multi-stemmed erect shrub to 4 m. Current year's branchlets densely short-silky, hairs persisting for the current year, light greyish red (UCL18)). Flower buds 2–4 mm long, 2.1 mm wide, 1.8 mm deep, ovoid, keels with 2 keels, light greyish red, with dense short-silky hairs. Leaf buds also with dense short-silky hairs. Leaves alternate. Stipule persistent, 1.5 mm long, very narrowly ovate, entire. Petiole 3–5 mm long, dense short-silky hairs all over, glands absent, base pinkish red, not enlarged. Emerging leaves with dense long-silky hairs on the lower surface, moderately dense long-silky hairs on the upper surface. Proximal leaves entire. Leaf lamina 25–30 mm long, 10–11 mm wide, length to width ratio 2.3–3.0:1, narrowly elliptical or oblong-elliptical; base rounded; apex acute and hooked downward; leaf galls absent; margins entire, with glands on margin, plane; upper lamina surface slightly bullate due to impressed veins, slightly glossy, sparsely short-silky hairy, stomata absent; lower lamina surface midvein raised, distinctly glaucous, moderately densely long-silky. Catkins female, emerging before leaves. Flowering branch 19 mm long, with 4 leaves. Female catkin 12–15 mm long, 6–7 mm diameter; catkin rachis not visible between flowers. Flower bract 1.6–1.8 mm long, 0.8 mm wide, dark red in the distal half, hyaline in the proximal half, flat; apex obtuse, long-silky hairs on both surfaces and margins. Female nectary 1, 0.7 mm long, 0.2 mm wide, yellow; ovary 2.2–2.4 mm long, glabrous or densely hairy, longer than flower bract; stipe 1.3–1.6 mm long; style base 0.4 mm long, style arms 0.2–0.4 mm long, unlobed, stigmatic surfaces pale yellow, sometimes tinted red.

 Recognition

Leaves are oblong-elliptical, with the apex bent downwards, the petiole pinkish red in summer. The underside of the leaf is moderately densely to densely long-silky hairy and appears silvery. Leaf margins are entire but have glands; they are not revolute when fresh (but finely revolute when dried). Branchlets are reddish and persistently densely short-silky hairy. Stipules are persistent, small, entire, and densely hairy.

Clones present in New Zealand are all female. Confusingly, the ovaries can be glabrous or densely hairy. The ovary has a long stipe.

There is no other Salix species in New Zealand with such small leaves (25–30 mm long) that are densely long-silky hairy on the underside. Other species with dense long-silky hairs have larger leaves (e.g. S. viminalis with leaves 70–235 mm long, and S. schwerinii with leaves 135–188 mm long).

Modern authors such as Skvortsov (1999) agree that Salix repens is a polymorphic species, including S. arenaria L. and S. rosmarinifolia L. Meikle (1984) agreed, but recognised var. repens, var. fusca Wimm. et Grab., and var. argentea (Sm.) Wimm. et Grab. in the UK. Some New Zealand plants in cultivation (e.g. PN307) exceed 3 m, taller than stated in European descriptions, but Meikle (1984) describes var. fusca as an erect shrub reaching 1.5 m with densely hairy ovaries.

 Distribution

In cultivation at Gisborne (Eastwood Hill 1965, Hackfalls Arboretum 1991), Southern North Island (Aokautere 1980, 2017), Canterbury (Christchurch Botanic Gardens 1971).

 Biostatus
Exotic

In the National Willow Collection it is represented by clones PN297 and PN307.

 First Record

First collection: CHR 156287, W. R. Sykes, 1965, Eastwood Hill Arboretum.

First publication: This publication.

 Phenology

Flowering: Early September–early October, possibly continuing to flower into summer.

 Cytology

Diploid, 2n = 38 (CCDB, based on eight counts), provisionally confirmed using flow cytometry with PN241, PN294, and PN307.

 Bibliography
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.
Meikle, R.D. 1984: Willows and poplars of Great Britain and Ireland. BSBI Handbooks No 4. Botanical Society of the British Isles.
Skvortsov, A.K. 1999: Willows of Russia and adjacent countries. Taxonomical and geographical revision. Univ. Joensuu Fac. Math. Nat. Sci. Rep. Ser. 39: 1–307.