The New Zealand Plant Conservation Network

Species

Alternanthera denticulata

Etymology

Alternanthera: From the Latin alternus 'alternate' and the Greek anthera 'anther', meaning alternating anther, probably in reference to the anthers being alternately fertile and barren.
denticulata: finely toothed

Common Name(s)

lesser joyweed

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

Alternanthera denticulata R.Br.

Family

Amaranthaceae

Flora Category

Vascular - Native

NVS Species Code

ALTDEN

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Has been incorrectly referred to Alternanthera sessilis (L.) Roem. & Schult. by past New Zealand authors

Distribution

Indigenous. Common in Australia (where the species was described from). There is some uncertainity as to its exact status in New Zealand, and while most of the populations seen appear to be indigenous, it seems likely that at least some locations may represent independent naturalisations from Australia (see Heenan & de Lange, N.Z.J.Bot. 42: 739-745 (2004))

Habitat

Coastal to lowland fertile wetlands, lake margins, river banks and around waterfalls, and in damp ground within forest, also a weed of drains, pig yards, and damp ground within urban areas

Features

Perennial herb. Stems prostrate to erect, somewhat lianoid, rooting at nodes, green flushed pink, glabrous to sparsely hairy, nodes tomentose. Leaves (20-)30-80 x 6-12 mm, narrowly elliptic or lanceolate, or linear to linear oblong, light green, yellow green or glaucous flushed pink, with midrib and lateral veins pink, glabrate, apex acute, margins distinctly denticulate. Spikes globular to shortly oblong 5-8 mm diam., clustered with 15-20 flowers. Flowers subtended by 1 bract and 2 bracteoles, these 1.5-2 x 0.6-0.8 mm, lanceolate, cream, glabrous, shortly acuminate to acute. Perianthe segments 2.3-2.4 x 0.6-0.8 mm, lanceolate, cream, glabrous, shortly acuminate to acute, anthers 0.15 mm long, yellow, style 0.1-0.2 mm, stigma capitate. Fruit 1.7-1.8 x 1.9-2.1 mm, cream flushed pink, obovoid, indehiscent. Seeds 0.9-1 x 0.8-0.9 mm, cream to yellow, with a light brown centre, compressed.

Similar Taxa

Closely related to A. nahui Heenan et de Lange. From which it differs by its more gracile growth habit and by the much broader, distinctly denticulate leaves. Hybrids between A. denticulata and A. nahui have been recorded.

Flowering

January - December

Flower Colours

Cream,Yellow

Fruiting

January - December

Propagation Technique

Easily grown from rooted pieces, cuttings and seed but inclined to become very weedy.

Threats

Not Threatened

Chromosome No.

2n = 28

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Urticles are dispersed by attaching to fur, feathers and clothing (Thorsen et al., 2009).

This page last updated on 14 Aug 2014