The New Zealand Plant Conservation Network

Species

Oxalis thompsoniae

Etymology

Oxalis: From the Greek word oxus meaning acid or sharp

Common Name(s)

Thompson's Oxalis

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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

Qualifiers

2012 - SO, Sp

Authority

Oxalis thompsoniae B.J.Conn et P.G.Richards

Family

Oxalidaceae

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None

Distribution

Indigenous: Kermadec (Raoul, Macauley), North, South and Chatham (Rekohu only) Islands. Also Australia and New Guinea

Habitat

Coastal to montane, in grassland, coastal shrub, grey scrub, open sites in forest, on cliff faces and associated rubble slopes. Occasionally in lawns and waste ground in urban situations

Features

Herb with prostrate or decumbent stems to 450 mm, glabrescent to moderately antrorse-hairy, sometimes with patent septate hairs present; tap root poorly developed; bulbils absent. Leaves cauline, 3-foliolate; leaflets subsessile, cuneate-obovate, 3-16 x 5-20 mm, bilobed, glaucous, glabrous to pubescent above, often densely hairy below, margins ciliate, sinus to 1/3 leaflet length, lobes oblong to slightly obovate, apices rounded, 3-10 mm apart; petioles 40-900 mm long, with simple antrorse hairs; stipules conspicuous, 1-3 mm long, apex rounded, ciliate. Inflorescences axillary 1-6-flowered; peduncles mostly shorter than leaves, sparsely antrorse-hairy; pedicels delfexed in fruit. Sepals oblong, 2-4 mm long, often ciliate; petals 4-12 mm long, yellow. Capsule cylindric, 5-16 mm long, erect, densely covered in retrorse-hairs interspersed with sparse, longer, patent septate hairs; seeds very compressed, smooth or shallowly ribbed.

Similar Taxa

Distinguished from Oxalis corniculata by the copious antrorse rather than retrorse stem and petiole hairs, smaller rounded, obtuse tipped, rather than very large, bluntly truncate stipules, which are evenly covered in hairs with the margins distinctly hairer, rather than glabrescent to evenly hairy. The leaves are copiously but finely hairy on both surfaces rather than hairy above glabrous beneath and usually glaucescent, rather than green, dark green, red-green or purple. The seeds of O. corniculata are distinctly ribbed, those of O. thompsoniae are not.

Flowering

September - June

Flower Colours

Yellow

Fruiting

July - June

Propagation Technique

Like many Oxalis inclined to be weedy in cultivation. This species is locally a problem in some parts of New Zealand but is rarely as weedy as the closely allied O. corniculata.

Threats

Not Threatened

Chromosome No.

2n = 24

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

This page last updated on 3 Jan 2014