Pityrodia byrnesii is a flowering plant in the mint family Lamiaceae and is endemic to Arnhem Land in the Northern Territory. It is a shrub with hairy, glandular stems, stalkless, flat leaves and fragrant, off-white, bell-like flowers with purple stripes inside the tube.
Pityrodia byrnesii is a shrub which grows to a height of about 1sigfig=1NaNsigfig=1 and which has its branches densely covered with glands and hairs. The leaves are arranged in whorls of three along the branches and are NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide. They are sticky due to glandular secretions, smooth on top with a distinct mid-rib on the lower surface.[1]
The flowers are fragrant and are arranged singly on a sticky, hairy stalk less than 2sigfig=1NaNsigfig=1 long. The flowers are surrounded by leaf-like bracts and bracteoles which are oblong to lance-shaped, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The sepals are NaNsigfig=1NaNsigfig=1 long and joined to form a bell-shaped tube with five lance-shaped lobes on the end. The lobes are lance-shaped, NaNsigfig=1NaNsigfig=1 long, hairy and sticky outside, and hairy inside. The tube is NaNsigfig=1NaNsigfig=1 and sticky and hairy outside, glabrous inside. The five petals are joined to form an almost cylindrical tube NaNsigfig=1NaNsigfig=1 long with five lobes on the end. The tube is off-white in colour with deep purple streaks on the upper lip. The lobes form two "lips" - the upper one with two lobes and the lower one longer with three lobes. The lower central lobe is the largest, NaNsigfig=2NaNsigfig=2 long and about 2sigfig=1NaNsigfig=1 wide. The four stamens extend slightly beyond the end of the tube, one pair slightly shorter than the other. Flowering occurs in most months and is followed by an oval-shaped, hairy, sticky fruit.[2]
Pityrodia byrnesii was first formally described in 1979 by Ahmad Abid Munir from a specimen collected near the East Alligator River crossing in the Northern Territory. The description was published in Journal of the Adelaide Botanic Gardens.[3] The specific epithet ("byrnesii") honours Norman Byrnes, an Australian taxonomist.[4]
This pityrodia occurs in Arnhem Land, near the East Alligator River, about 10sigfig=1NaNsigfig=1 south-west of Gunbalanya in the Kakadu National Park.
Pityrodia byrnesii is classified as "data deficient" under the Territory Parks and Wildlife Conservation Act 2000.