Conospermum longifolium, commonly known as the long leaf smokebush, is a species of flowering plant of the family Proteaceae and is endemic to New South Wales. It is a dense shrub or undershrub with linear to narrowly lance-shaped leaves, panicles of white flowers and velvety, cream-coloured to dark brown nuts.

Description

Conospermum longifolium is a dense shrub or undershrub that typically grows to a height of up to 2.5 m and is covered with fine hairs. The leaves are linear to narrowly lance-shaped with the narrower end towards the base, 35–190 mm long and 1–27 mm wide, glabrous and sessile. The flowers are arranged in panicles of up to 4 flowers on a peduncle 100–250 mm long with glabrous, egg-shaped bracteoles 1.6–3.8 mm long and 1.0–2.5 mm wide. The perianth is white, forming a tube 1.7–6 mm long. The upper lip is egg-shaped, 1.5–3.5 mm long and 1.8–2.5 mm wide, the lower lip joined for 1.2–2.5 mm with elliptic lobes 1.5–2.6 mm long and 0.8–1 mm wide. Flowering occurs in spring, and the fruit is a hairy cream-coloured to dark brown nut 2–3 mm long with golden hairs.

Taxonomy

Conospermum longifolium was first formally described in 1806 by James Edward Smith in his book, Exotic Botany, from a specimen collected from Port Jackson. The specific epithet (longifolium) means 'long-flowered'. In 1975, Lawrie Johnson and Donald McGillivray described 3 subspecies of C. longifolium in the journal Telopea, and the names are accepted by the Australian Plant Census:

Distribution and habitat

Long leaf smokebush grows in forest, woodland and heath on sandy soils on the coast and ranges of New South Wales between Newcastle, New South Wales and Ulladulla. Subspecies angustifolium is restricted to an area between Waterfall and Appin, subsp. longifolium mainly in coastal area between Port Jackson and Lake Conjola and subp. mediale mainly in the Blue Mountains between Putty and Moss Vale.