fbpx

Philotheca hispidula

Wax flower

Family: Rutaceae

A shrub to about 1 metre high, with slightly glandular-warty and finely-bristly branchlets.

It is mostly confined to the Greater Sydney Area, growing as far in the north-west in Wollemi National Park (east of Kandos), south-east to Sydney and Katoomba, stretching south to Mittagong-area, with some records near Bundanoon and Goulburn. Then, there is a disjunct patch of records west of Tuross Head and Narooma.
It is typically found in in dry sclerophyll shrublands, woodlands and forests on sandstone.

Philotheca spp. have simple and alternate leaves (a trait it shares with its relative Citrus), often with conspicuous oil glands and odorous.
In this species the leaves are narrow-ovate to narrow wedge-shaped with the narrower end towards the base, to 20 mm long and to 5 mm wide, with warts on the margins and the lower surface of the midrib, and with a distinct mucro (point) on the tip.

Philotheca spp. produce flowers in leaf axils or at the terminals, often reduced to single flowers with leaves in-between or in cymose or racemose groups. Flowers have 5 sepals (rarely 4) and 5 petals (rarely 4).
In this species, flowers are usually arranged singly in leaf axils (or sometimes in 2s or 3s), on a finely bristly peduncle to 15 mm long, white or pale pink petals with flowers up to 15 mm across, occurring mainly in Spring.

Philotheca is a genus of about fifty species all are endemic to Australia with species in every state except the Northern Territory.. Plants in this genus are shrubs with simple leaves arranged alternately along the stems, flowers that usually have five sepals, five petals and ten stamens that curve inwards over the ovary.
Philotheca is closely related to the well-known Boronia, the most obvious distinction being the presence of 4 petals in Boronia and 5 in Philotheca. The leaves are also opposite in Boronia and alternate in Philotheca.

The fruit of Philotheca is a schizocarp-capsule – which splits into equal segments on maturity which each segment called a coccus (plural cocci). In this species, the capsule is about 7 mm long with a beak about 3 mm long.

In the garden

This species is not commonly known in cultivation. It may be difficult to grow or requires further experimentation to realise its potential.

It may grow in dry, well drained soils in full sun or dappled light. It might also be useful to grow in a pot to start with.
Philothecas can be challenging to grow but often with more success than the related Boronias. They are very attractive in flower and well worth the effort.

In a garden situation, they grow best in well-drained soils in full sun. They can succumb quickly to poor drainage. Place in a well-drained sandy soil, in semi-shade to full sun, preferably on a slope. Lightly prune after flowering to maintain compact shape. Flowers attract bees and butterflies. Very useful in rockeries and sloping gardens.

Propagation

In common with most members of the Rutaceae, propagation from seed is difficult. Cuttings usually strike readily from current season’s growth but some species can be slow to form roots.

Other information

This species is reported to intergrade with Philotheca buxifolia in the wild.

Philotheca is a genus of about fifty species, all are endemic to Australia with species in every state except the Northern Territory.

Many plants formerly in Eriostemon are now in this genus.
See this link: https://en.wikipedia.org/wiki/Philotheca#cite_note-11 for a list of Philotheca species accepted by the Australian Plant Census as at April 2019.

Most Philotheca plants would die in a fire and regenerate from the seedbank.

Philotheca – was first described by Edward Rudge in 1812. As there are some reported variations on the meaning – the Latin of Rudge was transcribed for these profiles as follows: all as in Eriostemone, but the habit is very different from that of the ericoid branches; The terminal flowers and the filaments below, enlarged into the naked box, whence the name.
It has been reported that Psilos (ψιλός) refers to “naked” or “bare” in Ancient Greek. Philos (φίλος) in Greek tends to mean “friend”. Philia (φιλία) in Ancient Greek means “highest form of love”
The suffix -theca refers to “box” or “case” in Ancient Greek.
Hence, it is thought the name means “naked-box” or “loving-box” referring to the condition of the 10 (or 8) stamens that are fused at the base and forming a box-like structure. (Note: this is not the case in all species with some having free stamens).

hispidula – Latin referring to “hispid” meaning “bristly”, “rough”, “hairy” – often referring to stiff hairs which are present on the stems of this species.

This species is not considered to be at risk of extinction in the wild.

Plants of South-Eastern NSW – Philotheca hispidula profile page
https://apps.lucidcentral.org/plants_se_nsw/text/entities/philotheca_hispidula.htm

NSW Flora Online (PlantNET) – Philotheca hispidula profile page
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Philotheca~hispidula

Wikipedia – Philotheca hispidula profile page
https://en.wikipedia.org/wiki/Philotheca_hispidula

By Jeff Howes, edited Dan Clarke