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Philotheca buxifolia

Wax flower

Family: Rutaceae

Philotheca buxifolia is a shrub potentially growing to a height of 1.5 metres, often with a narrow spread.

It is found naturally in coastal areas of NSW, between Gosford and Ulladulla. There are also a few records as far west as Lithgow and Katoomba.

It is typically found on shallow sands and Hawkesbury Sandstone in coastal heathland, shrubland and dry sclerophyll woodland.

The branchlets are round with stiff hairs.

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, leaves are round to broadly elliptic or obovate (the narrower end towards the base), to 12 mm long and wedge-shaped or heart-shaped near the base, dark to olive-green, sometimes with a pointed apex.

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 produced solitarily, each flower on a pedicel to 5 mm long, petals are white to pink, with flowers up to 30 mm across, occurring from winter to spring.

The fruit of Philotheca is a schizocarp-capsule – which splits into equal segments on maturity which each segment called a coccus (plural cocci). The capsule consists of 1 to 5 cocci which split open to release small brown to black seeds.

In the garden

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 it grows best in a 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. This one is very attractive if it can be established. The flowers are very showy and the foliage is very architectural.

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

There are three subspecies which are accepted by the Australian Plant Census:
P. buxifolia subsp. buxifolia – commonly known as Box-leaf Waxflower has leaves are round to broadly elliptical, not folded lengthwise and have a heart-shaped base, and is mainly found in the Sydney area
P. buxifolia subsp. falcata has leaves that are round to broadly elliptical, not folded lengthwise and have a heart-shaped base; only occurring in the Jervis Bay area;
P. buxifolia subsp. obovata has obovate leaves (with the narrower end towards a wdge-shaped base), occurring near Gosford and near Ulladulla.

Philotheca is a genus of about fifty species, all are endemic to Australia with species in every state except the Northern Territory. Species are shrubs with simple leaves arranged alternately along the stems, flowers that usually have five sepals, five petals and usually 10 (sometimes 8) stamens that curve inwards over the ovary. Often the base of the stamens are fused but sometimes free.

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.

Cultivars are available such as:
• ‘Cascade Of Stars’ – a dwarf form
• ‘Starstruck’ – a taller form

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).

buxifolia – from Latin buxus = box-tree and folius = leaf (referring to its leaves being similar to those of the European Buxus or Box).

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

Wikipedia – Philotheca buxifolia profile page
https://en.wikipedia.org/wiki/Philotheca_buxifolia

Australian Plants Society – Sutherland Group Coastal Plants CD Resources – Philotheca buxifolia profile page
https://sutherland.austplants.com.au/rnp/pl34.htm

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

By Jeff Howes, edited Dan Clarke