Leionema elatius is a medium to large shrub, reaching 5 metres potentially, with a spread up to 3 metres.
In NSW, it is found mostly in the north coast botanical subdivision, north from Buladelah, extending slightly west into the coastal hinterland with some records on the tablelands towards Tenterfield and Armidale, and northwards to Queensland where it only just crosses the border, growing around Springbrook.
It grows in dry to wet sclerophyll forest as well as rainforest.
Leionema spp. have characteristics matching those of other similar Rutaceae genera, eg: Philotheca, Phebalium, Crowea; i.e., simple and alternate leaves, usually with oil glands.
In this species, leaves are small, about 3.5 cm long by 1 cm wide, mid to dark green, oblanceolate to obovate or spathulate and strongly aromatic when crushed; with upper surface smooth and glossy and the midrib is prominent on the undersurface.
Leionema spp. have 5-merous flowers; i.e. 5 sepals, 5 petals and usually 10 stamens surrounding 5 carpels, with an overall attractive star-shaped appearance. Flowers can be produced in leaf axils or branch terminals, in cymose clusters or solitary.
In this species, flowers are white, about 1 cm across and held in terminal clusters. Blooms are profuse and conspicuous appearing in spring.
The fruit of Leionema is a schizocarp-capsule – which splits into equal segments on maturity which each segment called a coccus (plural cocci). The capsule is approximately 4 mm long in this species.
This species is not ovelry popular in cultivation. Check with native nurseries and online for availability.
The illustrated specimen, from our cold climate garden (near Armidale), is the former subspecies. This specimen is surviving, thriving and blooming bounteously in heavy shade.
A light pruning after flowering is beneficial.
There is a popular cultivar called Leionema ‘Green Screen’ which is a hybrid of L. lamprophyllum and L. elatius.
Propagate from cuttings.
Two subspecies are currently recognised in NSW:
Leionema are a genus of 28 known species, 27 of which are endemic to Australia, with 1 species endemic to New Zealand. These species have been previously classified in the genus Eriostemon and Phebalium. NSW currently has 18 species.
Leionema differs by not having anthers with an apical point or gland, as well as free sepals on the flowers and small bracteoles on the middle to upper part of flower stalks (pedicels).
Most Leionema spp. would likely die in a fire and regenerate from seed. Some basal regrowth or stem-reshooting may be possible.
Leionema – from Greek leios (λείος), meaning “smooth”, and nema (nήμα), a thread, referring to a ‘hilar strand’; a small piece of tissue joining the hilum (a scar on the side of the seed) to the ovule.
elatius – Latin meaning “elevated” or “lofty”. Ferdinand von Mueller first described this species as Eriostemon elatior and stated in the description that it came from an elevated area near Tenterfield.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Leionema elatius profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Leionema~elatius
Wikipedia – Leionema elatius profile page https://en.wikipedia.org/wiki/Leionema_elatius