Achyranthes velutina
Common name
Devil’s horsewhip
Synonyms
Achyranthes indica (L.) P. Mill., Centrostachys aspera (L.) Standl.
Family
Amaranthaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
ACHVEL
Chromosome number
2n = 42
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | At Risk – Naturally Uncommon | Qualifiers: SO
Previous conservation statuses
2009 | Non-resident Native – Coloniser | Qualifiers: SO
2004 | Non-resident Native – Coloniser
Distribution
Known in a natural state only from Macauley Island in the southern Kermadec Island group. A. velutina is known from throughout the Pacific. It is A. velutina not A. aspera L. that was recorded once as naturalised from Silverdale in North Auckland in 1960.
Habitat
Amongst sea bird burrows on the margisn of steep cliffs in association with grasses and sedges.
Features
Small, much branched, monoecious shrub. Rootstock stout, woody. Stems somewhat succulent at first, ribbed becoming basally woody with age ribbed, densely covered in velutinous, appressed hairs. Petioles 5-10 mm long, pink, fleshy, velutinous, basal abscission zone evident. Leaves opposite, spreading to decurved, densely clustered toward branch tips, 40-50 x 25-30 mm, dark green, green or purple-grey, margins often, suffused with pink or red, mostly broadly ovate, ovate-orbicular or elliptic; apex blunt to abruptly subacute, sometimes shortly apiculate; base attentuate; lamina fleshy, veins distinct, often purple, upper and lower surfaces silky canescent, margins crenulate to crenate. Inflorescence a terminal erect spike, 150-200 mm long. Peduncle 15 mm long, fleshy, white-villous; spike rachis fleshy, white-villous to purple-villous; flowers bisexual, retrorse, sessile, c. 180-200 per spike, initially spaced at 10 mm intervals this diminishing to < 1 mm intervals toward inflorescence apex. Bracts persistent on rachis, 3-3.5 x 0.5-1 mm, ovate to lanceolate, strongly retrorse, chartaceous, weakly keeled near apex only, pale white, margins entire, apex acute, sometimes with a small 0.1-0.2 mm long pale yellow mucro. Bracteoles 2; abscissing with senescent flowers; 0.2-1 mm long, broadly ovate, chartaceous hyaline, lustrous, pale caramel; margins entire; strongly keeled, keel lustrous, caramel brown, extending well beyond bract as a hardened, channelled, strongly recurved, falcate spine 4-5 mm long. Perianth segments (sepals) 5, lancelate, central portion pale caramel-brown, distinctly pink-tinged, margins pale yellow or off-white opaque, hayline; segments subequal, 4.5-6 mm, channelled. Stamens 4, fused at base, filaments 0.5-1 mm, alternating with 4 narrowly spathulate 0.4 x 0.6 mm white-hyaline, petaloid, fimbriate-margined pseudostaminodes; anthers 0.4-0.6 mm, yellow. Style 0.6-1 mm, pink to pale orange, arising from a fleshy papillate style base 0.8 mm diameter; stigma brown, truncate. Utricle 2-2.5 mm, dark brown, turbinate, chartaceous, surmounted by the dry somewhat woody, style base. Seed 1.2-1.8 x 0.9-1.2 mm, dark chesnut brown, ovoid to ellipsoid.
Similar taxa
None. Macauley Island plants were initially treated as A. aspera (de Lange et al. 2004) adopting a broad circumscription advocated by most world flora treatments. Since then it is evident that A. aspera s.s. is distinct from Macauley plants which are now referred here to A. velutina (Barkla et al. 2008). Achyranthes aspera differs from A. velutina by its annual, more gracile growth habit, smaller size, and much less pigmented, glabrescent foliage. It is not known from New Zealand.
Flowering
Throughout the year
Flower colours
Orange, Red/Pink
Fruiting
Throughout the year
Life cycle
Spiny utricles are dispersed by attaching to fur, feathers and clothing (Thorsen et al., 2009)
Propagation technique
Easy from cuttings and seed. Potentially an aggressive weed in warm climates.
Threats
This species is only known from a single natural occurrence in New Zealand, Macauley Island in the Kermadecs. It is under no obvious threat and is apparently a recent example of a natural long distance dispersion with subsequent successful establishment on this island.
Where To Buy
Not commerically available.
Taxonomic Notes
The North Island record of Achyranthes aspera in the Webb et al. (1988) is also referred here to A. velutina, and in what is perhaps a rather unusual situation for the flora of New Zealand, is regarded as naturalised. Macauley plants are regarded as indigenous (see de Lange et al. 2004; Barkla et al. 2008).
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 1 January 2005. Description from de Lange et al. 92004) - as Achyranthes aspera (see taxonomic notes)
References and further reading
Barkla, J.W., P.J. Dilks, T.C. Greene and R. Griffiths 2008 Homalanthus polyandrus (Euphorbiaceae) on Macauley Island, southern Kermadec Islands, with notes on that island’s vascular flora. New Zealand Journal of Botany 46: 373–379.
de Lange, P.J., R.P. Scofield and T.C. Greene 2004 Achyranthes aspera (Amaranthaceae) a new indigenous addition to the flora of the Kermadec Islands group. New Zealand Journal of Botany 42: 167–1773.
Webb CJ, Sykes WR, Garnock-Jones PJ 1988. Flora of New Zealand. Vol. IV. Botany Division, DSIR, Christchurch.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 2009 Vol. 11 No. 4 pp. 285-309
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Achyranthes velutina Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/achyranthes-velutina/ (Date website was queried)