Persoonia lanceolata, commonly known as lance-leaf geebung, is a shrub native to New South Wales in eastern Australia. It reaches 3 m (9.8 ft) in height and has smooth grey bark and bright green foliage. Its small yellow flowers grow on racemes and appear in the austral summer and autumn (January to April), followed by green fleshy fruits (known as drupes) which ripen the following spring (September to October). Within the genus Persoonia, P. lanceolata belongs to the lanceolata group of 58 closely related species. It interbreeds with several other species found in its range.
The species is usually found in dry sclerophyll forest on sandstone-based nutrient-deficient soil. It has adapted to a fire-prone environment; plants lost in bushfires can regenerate through a ground-stored seed bank. Seedlings mostly germinate within two years of fires. Several species of native bee of the genus Leioproctus pollinate the flowers. Swamp wallabies are a main consumer of its fruit, and the seeds are spread in wallaby faeces. Its lifespan ranges from 25 to 60 years, though difficulties in propagation have seen low cultivation rates.
Persoonia lanceolata was officially described in 1799 by Henry Charles Andrews from a plant grown from seeds by L. Wilson in Islington. Andrews also described some plants which he had grown from seed in a nursery in Hammersmith as P. latifolia, which turned out to be the same species. The specific epithet is the Latin word lanceolata, meaning "spear-shaped", and refers to the shape of the leaves. Lance-leaf geebung is the common name. The term geebung is derived from the Dharug language word geebung. German botanist Otto Kuntze coined the binomial name Linkia lanceolata in 1891, from Cavanilles' original description of the genus description Linkia, but the name was eventually rejected in favour of Persoonia. The horticulturist Joseph Knight described this species as the privet-like persoonia (Persoonia ligustrina) in his controversial 1809 work On the cultivation of the plants belonging to the natural order of Proteeae, but the binomial name was declared an illegitimate name as it postdated Andrews' description and name. Robert Brown used Andrews' name in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen.
In 1870, George Bentham published the first infrageneric arrangement of Persoonia in Volume 5 of his landmark Flora Australiensis. He divided the genus into three sections, placing P. lanceolata in P. sect. Amblyanthera. The genus was reviewed by Peter Weston for the Flora of Australia treatment in 1995, and P. lanceolata gave its name to the lanceolata group, a group of 58 closely related species with similar flowers but very different foliage. These species often interbreed with each other where two members of the group occur, and hybrids of P. lanceolata with P. katerae, P. levis, P. linearis, P. stradbrokensis and P. virgata have been recorded. The glaucous-leaved P. glaucescens was formerly considered a subspecies of P. lanceolata, but no intermediate forms have been recorded from where the two taxa grow together near Hill Top in the Southern Highlands. P. lanceolata has seven chromosomes, as do most other members of the genus, and they are large compared to those of other proteaceae.