About Grevillea alpina Lindl.
Grevillea alpina Lindl. displays considerable variation across its form, leaves, and flowers. Mature plants reach between 0.3 and 2 metres (0.98 and 6.56 ft) in height. Leaves can be linear, oblong, or elliptic, typically measuring 0.5 to 2 centimetres (0.20 and 0.79 in) long and 1.5 to 4 millimetres (0.059 to 0.157 in) wide. Hairs may be present or absent on both leaf surfaces, and leaf edges are often curved backwards or revolute. Flower colour is one of the species' most variable traits: the main colour of the perianth is most commonly red, orange, or pink, and more rarely yellow or cream. Colour often transitions along the length of the perianth, resulting in common red-yellow or red-cream combinations. In the species' native range, flowering occurs primarily from August to December. After flowering, plants produce hairy, leathery, ovoid fruit called follicles that are 8.5 to 12 millimetres (0.33 to 0.47 in) long. These follicles split open to release winged seeds. Grevillea alpina is widespread in Victoria, Australia, extending north from Melbourne into New South Wales through Albury, and reaches as far north as Canberra, where it grows on Black Mountain. Its westernmost native occurrence is in the Grampians, Victoria. It grows naturally in woodland, heathland, and mallee habitats. In their 1995 work The Grevillea Book, authors Peter Olde and Neil Marriott identified five informal forms of the species: the Grampians form; the type form with bright orange and yellow flowers; the Southern Hills form, found in areas surrounding Melbourne including Lerderderg Gorge, Kinglake, Mount Slide, Mount Evelyn, the Dandenong Ranges, and Cardinia; the Goldfields form, which occurs in Castlemaine, Bendigo, and Whroo Forest; the Northern Victorian form, found in areas including the Strathbogie Ranges and the Warby Ranges; and the small-flowered form, found in Beechworth, Chiltern, Albury, and Canberra. Plants from Tooborac were originally classified as the small-flowered form, but the authors now believe they may represent a separate informal form. Naturally occurring hybrids between G. alpina and G. lavandulacea, G. dryophylla, and G. obtecta have been recorded. In New Zealand, hybrids between G. alpina and Grevillea rosmarinifolia have become naturalised. Ecologically, honeyeaters are thought to be the major pollinators of G. alpina. Honey bees have been observed feeding on the species' nectar, but can do so without touching the pollen presenter. This species was first introduced to cultivation in England in 1856, and was in cultivation at the Royal Botanic Gardens, Melbourne by 1858. Though widely grown, it has a reputation for being short-lived. This issue is more severe in humid climates with summer rainfall, and can be resolved by grafting G. alpina onto various rootstocks. G. alpina grows best in dry environments and does not tolerate excess moisture well. Regular pruning starting from a young age encourages denser growth and reduces excess woodiness. Plants can be readily propagated from pre-treated seed, though seed collected from garden-grown plants often produces hybrid offspring. The species hybridises readily with Grevillea rosmarinifolia, Grevillea juniperina, and Grevillea lavandulacea. Propagation from cuttings is the preferred method to preserve the traits of specific forms and cultivars. In 2003, the fungal disease Phytophthora palmivora was detected in plant nurseries in Sicily, causing root rot and death in potted Grevillea cultivars; Grevillea alpina plants were the most severely affected among these cultivars.
