The New Zealand Plant Conservation Network

Species

Sophora microphylla

Etymology

Sophora: after the Arabic name for a similar tree
microphylla: small leaf

Common Name(s)

Kowhai, weeping kowhai, small-leaved kowhai

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Sophora microphylla Aiton

Family

Fabaceae

Brief Description

A common kowhai tree bearing leaves 30-50mm long that have spaced equal-sized leaflets 4.5-12.5mm long and with bunches of drooping yellow flowers and dry ridged and knobbly seed pods 50-200mm long containing hard yellow seeds. Juveniles with zig-zagging branches.

Flora Category

Vascular - Native

NVS Species Code

SOPMIC

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

Edwardsia microphylla (Aiton) Salisb., Edwardsia grandiflora var. microphylla (Aiton) Hook.f., Sophora tetraptera var. microphylla (Aiton) Hook.f.; Sophora microphylla Aiton var. microphylla; Sophora microphylla Aiton subsp. microphylla; Sophora microphylla Aiton subsp. microphylla var. microphylla

Distribution

Endemic. Throughout the main islands of New Zealand but scarce in parts of Northland.

Habitat

In the North Island, especially the northern half this is a species of mainly riparian forest. South of about Hamilton it can be found in a diverse range of habitats from coastal cliff faces and associated wetlands to inland grey scrub communities. Scarce to absent over large parts of the eastern North Island from about East Cape south to the northern Wairarapa.

Features

Tree up to 25 m tall, usually a single trunk. Branches weeping, and spreading. Juveniles divaricating and/or strongly flexuose, and interlacing. Leaves on seedlings sparsely to moderately leafy, 3-5.8 x 2.3-4.9 mm, broadly obovate to orbicular, glabrous to sparely pubescent, distant, not crowded or overlapping. Adult leaves up to 150 mm long, imparipinnate, moderately to sparsely hairy, hairs, straight, appressed. Leaflets 30-50, not crowded or overlapping, distant, 4.5-12.5 x 2.3-5.7 mm, elliptic, broadly elliptic, obovate to ovate, sometimes orbicular, distal and proximal leaflets of similar size. Inflorescences racemose with up to 7 flowers. Calyx 5-11 x 7-10 mm, cupulate. Flowers yellow, keel petal blade 18-50 x 7-13 mm, wing petal blade 18-50 x 6-11 mm, standard petal blade 20-35 x 14-25 mm; petals with distinct claws 4-8 mm long. Fruit 50-200 mm long, 4-winged, brown, with up to 12 seeds. Seeds 5.5-8.5 x 4.-5.5 mm, oblong, elliptic to orbicular, yellow to light yellow-brown.

Similar Taxa

Can be distinguished from the other Kowhai species by the divaricating/filiramulate juvenile and arborescent adult, leaves > 30 mm, leaflet pairs > 6, these sparsely to moderately hairy, with the distil and by the obvious petiolule.

Flowering

(May-) August-October

Flower Colours

Yellow

Fruiting

October -May

Propagation Technique

Easy from seed, provided the hard seed shell is nicked first with a knife or rubbed with sandpaper to expose the endosperm. Soaking seed treated this way overnight often helps speed up germination. Can be grown with difficulty from cuttings.

Threats

The main threat that faces all wild New Zealand kowhai species is the risk posed through planting for revegetation and horticultural purposes of hybrid material, foreign species, such as the Chilean Pelu (S. cassioides) and also of kowhai species outside their natural range. In many places S. microphylla occurs as isolated stands within otherwise cleared alluvial forest, and in this situations the loss of trees over time is inevitable. The species is genuinely uncommon in Northland, and in that area inadequately represented within reserves and other conservation land.

Chromosome No.

2n = 18

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 6 Dec 2014