Gratiola sexdentata
Common names
Gratiola
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
White, Yellow
Detailed description
Terrestrial to semi-aquatic glabrous to finely viscid-pubescent, erect to widely spreading perennial herb forming patches up to 300 x 300 mm. Stems mostly erect, stout, sparingly to heavily though laxly branched from base, dark purple or maroon often with dark spots or green with purple spots (rarely completely green). Leaves sessile to subsessile, opposite, 6-30 x 4-16 mm; dark green above with purple stitch marks along lamina (rarely bright green without stitch marks), undersides paler, often purple spotted; lamina ovate to lanceolate or suboblong, very rarely linear-lanceolate, margins entire, subentire or with distant fine, triangular-teeth. Flowers axillary on slender peduncles up to 10 mm long. Calyx-lobes 4-6 mm long, darkly purple-green, often with darker spots, or bright green; narrow-lanceolate, more or less attenuate, obtuse, to narrow ovate-lanceolate. Corolla 10-16 mm long, with corolla tube 8-14 mm long and corolla lips < tube; externally white often with a yellowish base, internally with a yellow throat, usually with 4-8 fine purple lines extending from lips to corolla base; rarely corolla completely white. Anthers connivent, cells parallel, transverse; staminodes filiform. Capsule c.5 mm long; dark purple-green with dark spotting or bright green, drying greyish; more or less ovoid-globose, initially fleshy, maturing chartaceous. Seeds numerous.
Similar taxa
Has been much confused with the South American G. peruviana and Australian G. latifolia but it does not seem to be close to either of these species, differing consistently by its smaller, ovate-lanceolate leaves with purple stitch marks along the margins, dark purple spotted glabrous to hairy stems, and longer, larger flowers. However, further study is needed. From the other New Zealand species it could perhaps be confused with G. pubescens but that species has all its vegetative parts covered in fine viscid hair. G. pedunculata is similar but has smaller pedicellate flowers, glandular sticky indumentum, no purple stitch marks on the leaves, and much smaller flowers. Small forms of G. concinna have also been confused with it.
Distribution
Endemic. Widespread throughout the North and South Islands, can be locally common but often absent from large parts of the country
Habitat
Lake, pond, tarn and river margins where it grows in marginal turf communities or on recently exposed mud or silt. Also present in wetlands where it grows along slow flowing streams, in pools of water or amongst sedges and reeds (but only in open sites it dislikes heavy shade). Occasionally collected from muddy pools within alluvial forest.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened
Detailed taxonomy
Family
Synonyms
Gratiola glandulifera Colenso
Taxonomic notes
Gratiola sexdentata - as currently circumscribed remains a highly variable species and this variation warrants further study.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
Year round
Fruiting
Year round
Life cycle and dispersal
Mucilaginous seeds are dispersed by water and possibly wind and attachment (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed, rooted pieces or stem cuttings. Needs to grow in water.
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]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Other information
Etymology
gratiola: Little beauty
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.
GRASEX
Chromosome number
2n = 90
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | At Risk – Regionally Declining | Qualifiers: DPR, DPS, DPT, RR, Sp
Referencing and citations
References and further reading
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 11: 285-309
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 4 May 2006. Description by P.J. de Lange
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Gratiola sexdentata Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/gratiola-sexdentata/ (Date website was queried)