Dichondra micrantha
Common names
Mercury Bay weed
Family
Convolvulaceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
Conservation status
Not applicable
Distribution
North Island: North. Auckland (Kawau Island) to Wellington; South Island: Christchurch.
Habitat
Widely planted as a lawn in warmer parts of New Zealand and in many places it has thrived and spread naturally to a limited extent.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Detailed description
Perennial herb, with most parts densely hairy; hairs white, ± appressed, forked. Stems stoloniferous, freely branching, purplish, forming extensive mats or low cushions to 5 cm high. Lf internodes 1-2 cm long; petioles erect or nearly so, to 6 cm long, short on very exposed stolons. Lamina (5)-10-30 mm diam., suborbicular to reniform, membranous, glabrous or nearly so and dull above, with appressed hairs below; veins raised beneath, not impressed above; base broad-cordate; apex rounded or slightly emarginate. Peduncles 5-15 mm long, bract very small and inconspicuous. Calyx c. 2 mm long, densely hairy outside; lobes alternately linear-oblong and ovate-oblong, obtuse to subacute. Corolla 4-5 mm diam., greenish white, lobed to c. 1/2 way; lobes narrow-oblong to lanceolate, = calyx lobes at anthesis, becoming > calyx lobes. Anthers violet or violet-margined. Ovary densely hairy. Capsule usually deeply 2-lobed, with 1-(2) seeds per loculus, 2-2.5 × 4-5 mm, more rarely only 1 locule developed, indehiscent, slightly to strongly hispid, > calyx. Fruiting calyx to 3 mm long, fruiting peduncle recurved. Seeds c. 1.5 mm long, yellow to dark brown.
Similar taxa
Disnighished from the native Dichondra by the glabrous to glabrate leaves and the habit - found in urban lawns.
Year naturalised
1978
Origin
West Indies, S. North America
Etymology
dichondra: Two seeds
micrantha: Tiny flower
This name may be incorrectely used for the exotic Dichondra in New Zealand. Previously reffured to as the indigenous D. repens.
Attribution
Fact sheet prepared by Marley Ford (3 October 2022). Brief description, Distribution, Habitat, and Features sections copied from Webb et al. (1988).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.
References and further reading
Webb C.J., Sykes W.R., & Garnock-Jones P.J. (1988). Flora of New Zealand Volume 4. DSIR, Botany Division.