''Prostanthera nudula'', commonly known as Mount Illbillee mintbush, is a species of flowering plant in the family

Lamiaceae The Lamiaceae ( ) or Labiatae are a family of flowering plants commonly known as the mint, deadnettle or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil, mint, rosemary, sage, savory ...

and is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to South Australia. It is a shrub with branches that become spiny, narrow elliptic leaves and pale cream-coloured flowers with yellow dots inside.

Description

''Prostanthera nudula'' is an erect to scrambling shrub that grows to a height of with branches that become rigid spines as they age. The leaves are narrow elliptic, long and wide on a petiole long. The flowers are arranged on

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

long with

bracteoles In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

long near the base. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s are yellowish green, forming a tube long with two lobes, the lower lobe long and the upper lobe long. The petals are pale cream-coloured with yellow spots, long, the central lower lobe long and about wide. The lower lateral lobes are about long and wide and the upper lip is broadly egg-shaped, long and about wide. Flowering occurs from September to October.

Taxonomy

''Prostanthera nudula'' was first formally described in 1957 by

Enid Lucy Robertson Enid Lucy Robertson () (20 November 1925 - 10 July 2016) was a systematic botanist, curator of herbaria, and conservationist from South Australia. In the 1970s, she developed a new and innovative way to manage reserves, writing the ''Watip ...

from an unpublished description by

John McConnell Black John McConnell Black (28 April 1855 – 2 December 1951) was a Scottish botanist who emigrated to Australia in 1877 and eventually documented and illustrated thousands of flora in South Australia in the early 20th century. His publications assi ...

. The description was published in the second edition of the ''Flora of South Australia'' from specimens collected by J.B. Cleland in the

Everard Ranges The Everard Ranges, officially known as The Everard Ranges, is a range of low rounded granite hills located in the Australian state of South Australia in the Aṉangu Pitjantjatjara Yankunytjatjara lands about west of Mintabie. It is of P ...

in 1950.

Distribution and habitat

Mount Illbillee mintbush grows amongst granite outcrops, usually near watercourse. It is relatively common in the Everard Ranges and is also found in the

Musgrave Ranges Musgrave Ranges is a mountain range in Central Australia, straddling the boundary of South Australia (Anangu Pitjantjatjara Yankunytjatjara) and the Northern Territory (MacDonnell Shire), extending into Western Australia. It is between the Great V ...

References

{{Taxonbar, from=Q15355176 nudula Flora of South Australia Lamiales of Australia Plants described in 1957