Eremophila pinnatifida (also known as Pinnate-leaf Eremophila) is listed as Endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and as Declared rare Flora under the Wildlife Conservation Act 1950.
The main factors that are the cause of the species being eligible for listing in the Endangered category are that it has a restricted distribution that is precarious for its survival. The number of mature individuals was estimated to be fewer than 500, and the Pinnate-leaf Eremophila is threatened by continuing decline in habitat quality and area of occupancy
The Pinnate-leaf Eremophila is an erect shrub growing to approximately 1 m tall. Branches are densely hairy, with the hairs short, yellow, and tipped with glands. Leaves are erect and occur in whorls of 3 that obscure the branches. Leaves are oval to oblong in shape, with deeply lobed margins. Leaves are approximately 5 – 9 mm long x 3 – 5 mm wide. Both surfaces of the leaf blade are densely covered with short, downy hairs; the surface of the leaf blade facing the stem bears numerous long white hairs. Flowers are 18 – 25 mm long, pale purple with the inside of the tube white with pale purple spots. The outer surface of the flower tube is densely covered with short, downy hairs. There are five sepals, the outer surface of each is densely covered with short, downy hairs. The fruit is dry, woody, and broadly oval. Seeds are oval-oblong, approximately 2.5 mm long, 0.7 mm wide, and very pale yellow-brown in colour.
The Pinnate-leaf Eremophila is known only from scattered occurrences in the area around Dalwallinu and there is a larger occurrence north of Wongan Hills. In 2002 the species was known from four populations with a total of approximately 460 mature plants. Three populations are known from road reserves. The species grows in red or brown clay loam in tall open woodland and shrubland with Eucalyptus salmonophloia (salmon gum), E. salubris (gimlet), Santalum acuminatum (quandong), Templetonia sulcata (flat mallee-pea), Eremophila species and Acacia merrallii.
The Pinnate-leaf Eremophila can flower from August to February, and seeds mature in June-July. The species is suspected have a lifespan of approximately 10 years. A level of habitat disturbance is apparently required for the species’ maintenance, as germination is stimulated by fire or soil disturbance. The low rate of seed production may be at least partly due to low genetic diversity and the age of the plants. In addition to fruit having low numbers of viable seeds, Eremophila species also possess germination inhibitors.
Information Source: Government of Australia, Department of Environment and Department of Parks and Wildlife Western Australia