Convolvulus verecundus f. verecundus
Common name
trailing bindweed, tussock bindweed
Synonyms
Convolvulus verecundus Allan subsp. verecundus
Family
Convolvulaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Lianes & Related Trailing Plants - Dicotyledons
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.
CONVER
Chromosome number
2n = 22
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.
2018 | Threatened – Nationally Vulnerable
Previous conservation statuses
2012 | At Risk – Declining | Qualifiers: DP
2009 | At Risk – Declining | Qualifiers: DP
2004 | Sparse
Distribution
Endemic. Eastern South Island only from the Clarence River (probably now Historic) south to Central Otago. Probably now most abundant in the Mackenzie Basin and upper Waitaki River Valley.
Habitat
Mainly montane (rarely lowland) (c.200 - 1000 m a.s.l.) sparsely vegetated short tussock, or on rock outcrops such as limestone, within regions subjected to regular summer-dry conditions. It has also been found in semi-arid habitats dominated by introduced weeds.
Features
Low-growing perennial herb, with creeping rhizomatous stems, short ascending to spreading branches, and lianoid stems up to 200 mm; lianoid stems with a sparse to moderate covering of retrorse hairs. Leaves in rosettes and alternate on stems, 6.5–12.0 × 4.0–12.5 mm, deltoid, deltoid ovate to ± broad-oblong, grey, grey-green, to silver grey, moderately to densely hairy with hairs antrorse and appressed; veins obscure; margin with 4–6 pairs of teeth, undulate; base truncate, obtuse, occasionally oblique or slightly cordate; apex usually retuse, occasionally obtuse; petiole channelled, sparsely to moderately covered with retrorse and antrorse hairs. Pedicel 5–30(–55) mm long, 0.4–1.2 mm diam., moderately hairy. Sepals 3.9–4.1 × 3.5–3.8 mm, obovate to ovate, green; abaxial surface sparsely to moderately hairy, adaxial surface glabrous; margin fimbriate and translucent; apex subacute to obtuse. Corolla 12–19 mm long in bud, 20–25 mm wide when open, white, rarely pink, five lobes fused their full length, lobe apex fringed with hairs; tube 5–8 mm long, pale green; abaxial surface with midline of petal with pink bands with sparse appressed hairs on upper half. Nectary annular, 0.3–0.4 mm tall, yellow. Style 2-cleft, white; fused portion 6.0–9.0 mm long, c. 0.2 mm wide; stigmata 2.5–4.0 × c. 0.5 mm. Ovary c. 1.0 × 1.0–1.2 mm, cream. Filaments 4.0–4.6 mm long, c. 0.5 mm wide at base, tapering to c. 0.2 mm at apex, white; margin with scattered short hairs on lower half; fused to base of corolla tube. Anthers 1.7–2.0 mm long, white. Capsule 5.8–6.2 mm long, 4.5–7.5 mm wide, chartaceous, globose, with 2–4 seeds, lower half enclosed in persistent calyx, style base remnant persistent. Seeds segment-shaped and broader toward apex with a rounded dorsal and two flattened lateral faces meeting at an acute ventral edge, or rounded and broadly obovate without distinct angles, almost triangular to terete in section; 2.8–3.9 × 2.4–3.0 mm; apex and base rounded; hilum concave. Testa black-brown overlaid and ornamented with grey nut-brown, dull, glabrous, moderately covered in low ridges and tubercules, sometimes forming ridges on margins
Similar taxa
Convolvulus waitaha and C. fracto-saxosa, from both of which it differs by its lianoid stems up to 200 mm long, more or less uniformly deltoid, deltoid-ovate to broad oblong leaves with smaller basal lobes, and which lack filiform or linear terminal lobes. Convolvulus verecundus f. glaberrimus differs by the glabrate brown-green rather than hairy silvery-grey leaves.
Flowering
November - January
Flower colours
Red/Pink, White
Fruiting
December - March
Life cycle
Seeds are wind dispersed (Thorsen et al., 2009).
Propagation technique
Difficult. Easily grown from fresh seed which germinates readily but does not thrive in cultivation. It particularly resents humid conditions. Probably best in a well drained pot within an alpine house.
Threats
Threats are complex, and varied. It cannot be doubted that this species has declined from the Waitaki Valley as a consequence of hydrodevelopment of that river system. It may also have gone extinct in Marlborough, where it appears to have always been scarce. Recent field work and accounts from field workers indicate that this species exists in naturally sparse, widely scattered and mostly stable populations (Heenan et al. 2003).
Etymology
convolvulus: From Latin convolvere, which means to twine around
Attribution
Fact sheet prepared by P.J. de Lange (5 September 2019). Description from Heenan & Molloy (2019).
References and further reading
Heenan, P.B.; Molloy, B.P.J.; de Lange, P.J. 2003: Species of Convolvulus (Convolvulaceae) endemic to New Zealand. New Zealand Journal of Botany 41: 447–457.
Heenan, P.B.; Molloy, B.P.J. 2019: Five new and Nationally Threatened taxa of Brachyscome, Cardamine, Convolvulus, Geranium and Ranunculus obligate to vulnerable limestone habitats, eastern South Island, New Zealand. Phytotaxa 415(1): 32-48.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Convolvulus verecundus f. verecundus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/convolvulus-verecundus-f-verecundus/ (Date website was queried)