Ackama nubicola
Common name
Turoa Onamata
Synonyms
None
Family
Cunoniaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Trees & Shrubs - Dicotyledons
Chromosome number
2n = 32
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 | Threatened – Nationally Critical | Qualifiers: CD, OL, RF
Previous conservation statuses
2009 | Threatened – Nationally Critical | Qualifiers: CD, RF, OL
2004 | Threatened – Nationally Endangered
Brief description
Rare small tree occurring above 500m in the Waima Forest. Leaves with 4-8 opposite pairs of toothed leaflets and a terminal leaflet and young leaves protected by an obvious oval cream scale. Flowers in dense sprays of pinkish-green flowers.
Distribution
Endemic. North Island, South Hokianga, Waima Forest.
Habitat
Apparently restricted to secondary regrowth within cloud forest at altitudes above 500 m. At present this species is only known from one site where it grows within valley heads, along cliff margins, at the base of rock outcrops and at the interface between forest and rough pasture. Typically the species grows in dense stands of 5-20 apparently even-aged trees. Most seedlings and juveniles have been found as low epiphytes on tree ferns. However, because the sole habitat has been until recently accessible to cattle, it is more likely that the seedlings observed have been those that survived because they were out of reach of these animals.
Features
Small tree 5-15 m tall, multi trunked and often suckering from base. Crown spreading, canopy foliage silvery-grey when viewed from a distance. Bark pale greyish white, streaked graphite grey, firm. Branches stout, sparse, erect. Stipules interpetiolar, long persistent, 14 x 18 mm, butter-yellow or cream, basally flushed purple, orbicular, fleshy, margin entire. Petioles 35-40 mm long, pulvinate. Leaves compound, leathery, 140-300 x 50-140 mm, initially wine-red or pink, rather sticky, maturing dark green above, somewhat silvery green below, leaflets (2-)4(-11) pairs, petiolules 10-20 mm, dark maroon; leaflets 30-150 x 35-100 mm, with middle pairs larger than all but the terminal leaflet, basal leaflet pair truncate, other pairs except terminal leaflet truncate or oblique; terminal leaflet cuneate, up to 100 x 50 mm, margins serrated, leaf domatia inconspicuous, vestigial, of the hair tuft type. Inflorescences axillary, paniculate 80-100 mm long, suberect to pendent. Flowers perfect, on short pedicels. Calyx (4-)5 merous, valvate; 0.8 mm long, sepals oblong-deltoid, fused, sparsely covered in appressed hairs. Petals (4-)5, off white to pink, 0.8 x 0.2 mm. Stamens 10, white to pale pink; anthers 0.2 mm diam., cream. Ovary ovoid 0.8 mm diam., covered in appressed hairs, the two carpels free almost to base. Styles 0.8 mm long, pale pink, falcate. Stigmas 0.2-0.4 mm, crimson, punctate. Fruit a broadly cylindrical to globose capsule 2.4-3 x 2-2.7 mm, initially cream-coloured drying honey-brown or dark brown. Seeds 4(-6) per capsule, reddish brown, 0.9 x 0.4 mm, ovoid.
Similar taxa
Makamaka (Ackama rosifolia) though similar is a smaller tree than A. nubicola, with smaller, narrower leaves which usually bear more leaflets. Ackama rosifolia has conspicuous hair-tuft pocket domatia located at the vein/midrib junction on the leaflet underside, while A. nubicola either lacks domatia completely or has very inconspicuous tufts of hair. The stipules of A. rosifolia are smaller than those of A. nubicola, green, deciduous and obovate to lanceolate, with prominent apical teeth, rather than creamy yellow, orbicular, entire and long persistent. Flowers are produced by A. rosifolia in spring and by A. nubicola in late summer to early autumn. Lastly, the maturing fruits of A. rosifolia are pink or carmine rather than cream.
Flowering
Appears to be February - March (flowering has been observed twice since it was discovered in 2000)
Flower colours
Red/Pink, White
Fruiting
Appears to be March-July, though exact time uncertain (fruit has been observed three times since the species was discovered in 2000)
Life cycle
Hairy carpels dispersed by wind (Thorsen et al., 2009).
Propagation technique
Softwood to semi hardwood cuttings taken in February. Although cuttings are easy to strike, and plants initially grow rapidly, they have proved difficult to maintain. This species seems to require cool conditions and ample moisture. It cannot tolerate drought and dislikes humidity. So far attempts to cultivate to it have met with varying degrees of success. It has proved to be rather fickle.
Threats
Possums are the main threat as they severely defoliate the trees, thereby preventing flowering and fruiting.
Etymology
ackama: Formed from its Maori name - maka-maka
nubicola: Cloud dweller
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (27 December 2002). Description adapted from de Lange et al. (2002).
References and further reading
de Lange, P.J.; Gardner, R.O.; Riddell, K.A. 2002: Ackama nubicola (Cunoniaceae) A New Species from Western Northland, North Island, New Zealand. New Zealand Journal of Botany 40(4): 525-534
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): Ackama nubicola Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/ackama-nubicola/ (Date website was queried)