Streblus banksii
Common names
ewekuri, large-leaved milk tree, tūrepo
Biostatus
Native
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Tree with grey spotted bark bearing dark green elliptical leaves that alternate along a slightly zig-zagged stem inhabiting warm areas, mainly on offshore islands. Leaves 3.5–8.5 cm long, paler underneath and vein network is easily visible. Flowers small, in clusters of long spikes. Fruit red, 6 mm wide.
Flower colours
Cream
Detailed description
Dioecious, robust tree or large shrub (depending on growing conditions) up to 12 m tall, usually with a broad canopy crown; trunk up to 0.8 m d.b.h., bark dark brown. Branches ascending at first then widely spreading; branchlets somewhat flexuous, wiry and pliant, initially puberulent and very lenticellate, later glabrate. Leaves of juvenile plants variable 20–60 × 10–30 mm, dark green above, paler beneath, elliptic-oblong , margins finely to deeply crenate, usually deeply lobed, pandurate, sinus obtuse; petioles up to 8 mm long. Leaves of adults 35–85 × 20–35 mm, dark green to yellow green, paler beneath, ovate to broadly ovate, ovate-elliptic, obtuse to subacute, margins crenate (very rarely lobed), petioles stout up to 10 mm long. Inflorescences axillary or terminal, spicate, solitary, paired or in threes; staminate up to 30 mm long, densely flowered, flowers rather densely close-set, almost imbricating, grey-green, perianth 4-partite, segments obtuse to rounded; pistillate similar, up to 25 mm long, flowers widely spaced, distichously arranged. Fruits up to 65 mm diameter, drupaceous, broad-ovoid, fleshy, flesh red.
Similar taxa
This species can and does hybridise with Streblus heterophyllus, and some mainland populations can be very hard to place in either species. S. banksii generally differs by its non-filiramulate growth habit, larger leaves and drupes.
Distribution
Endemic. New Zealand: North Island (mainly easterly from about Kaitaia to East Cape, Waikato and northern Hawkeʻs Bay, including islands of the Hauraki Gulf, thence somewhat disjunct reappearing in Horowhenua to Wellington and the western side of Wairarapa), South Island (northern parts where populations are known from Marlborough Sounds (mainly islands), Abel Tasman National Park, and also eastern Golden Bay).
Habitat
Coastal and lowland forests (0–200 m a.s.l.), preferring deep, fertile soils, large trees are often found on alluvial terraces. On offshore islands it seems more able to tolerate drier conditions and skeletal soils and may at times be found on steep cliff faces, rock ledges, or as stunted shrubs on cobble/boulder beaches.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 | At Risk – Relict | Qualifiers: Sp, CD, PD
Threats
It would appear that this species may once have been quite widespread. However, its current distribution is typically sparse and it is rarely common anywhere except on rodent-free offshore islands in the Hauraki Gulf and off the eastern Coromandel Peninsula. In mainland areas and on rodent infested islands plants are damaged by possum and goat browsing, and also by rodents which avidly eat the fruit, seed and emerging seedlings. In remnants being dioecious sex imbalance can be an issue. Successful island rodent eradication’s have allowed this species to restablish itself. It certainly responds rapidly to rodent removal.
Detailed taxonomy
Family
Moraceae
Synonyms
Paratrophis banksii Cheesem., Streblus heterophyllus var. ellipticus (Kirk) Corner, Paratrophis heterophylla var. elliptica Kirk
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
August–October
Fruiting
October–April
Propagation technique
Easily grown from fresh seed and can be grown from semi-hardwood cuttings (though success varies). A fast growing tree which makes an ideal specimen tree, and can be used as a hedge as it responds well to clipping. Prefers a deep, free draining, fertile soil. Once established it is very drought tolerant.
Other information
Etymology
banksii: Named after Sir Joseph Banks, 1st Baronet, GCB, PRS (24 February 1743 - 19 June 1820) was an English naturalist, botanist and patron of the natural sciences.
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.
STRBAN
Chromosome number
2n = 28
Previous conservation statuses
2017 | At Risk – Relict | Qualifiers: PD, Sp
2012 | At Risk – Relict | Qualifiers: Sp
2009 | At Risk – Relict | Qualifiers: Sp
2004 | Sparse
Referencing and citations
References and further reading
Allan HH. 1961. Flora of New Zealand, Volume I. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. Government Printer, Wellington, NZ. 1085 p.
Mitcalfe, B., Horne, C. 2002. Large-leaved milk tree, ewekuri, in the Wellington Region. Wellington Botanical Society Bulletin 48: 41–43.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange January 2005. Description adapted from Allan (1961).
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.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Streblus banksii Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/streblus-banksii/ (Date website was queried)