''Eucalyptus diversifolia'', commonly known as the soap mallee, coastal white mallee, South Australian coastal mallee, or coast gum is a species of mallee that is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to an area along the southern coast of Australia. It has smooth bark, lance-shaped adult leaves, flower buds in groups of between seven and eleven, white to creamy yellow flowers and cup-shaped fruit.

Description

''Eucalyptus diversifolia'' is a mallee that typically grows to a height of and forms a

lignotuber A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a respons ...

. It has smooth, mainly cream-coloured and grey bark. Young plants and

coppice Coppicing is the traditional method in woodland management of cutting down a tree to a tree stump, stump, which in many species encourages new Shoot (botany), shoots to grow from the stump or roots, thus ultimately regrowing the tree. A forest ...

regrowth have

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

, egg-shaped to elliptic leaves arranged in opposite pairs, long and wide. Adult leaves are arranged alternately, the same olive-green or bluish-green on both sides, lance-shaped, long and wide on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

long. The flower buds are arranged in groups of seven, nine or eleven in leaf

axil A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

s on an unbranched peduncle long, the individual buds on a

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

long. Mature buds are diamond-shaped, long and wide with a conical to beaked operculum. Flowering occurs between July and September or December to January and the flowers are white to cream-yellow flowers. The fruit is a woody, cup-shaped capsule long and wide, sessile or on a pedicel up to long with the valves about level with the rim. The seeds are smooth glossy brown and pyramidal.

Taxonomy

''Eucalyptus diversifolia'' was first formally described by the

botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

Aimé Bonpland Aimé Jacques Alexandre Bonpland (; 22 August 1773 – 11 May 1858) was a French List of explorers, explorer and botany, botanist who traveled with Alexander von Humboldt in Latin America from 1799 to 1804. He co-authored volumes of the scie ...

in 1814 and the description was published in his book ''Description des Plantes Rares cultivees a Malmaison et a Navarre''. Three

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

were described in 1987 by

Ian Wright Ian Edward Wright (born 3 November 1963) is an English media personality and former professional footballer. Wright enjoyed success with London clubs Crystal Palace and Arsenal as a forward, spending six years with the former and seven year ...

and

Pauline Ladiges Pauline Yvonne Ladiges (born 1948) is a botanist whose contributions have been significant both in building the field of taxonomy, ecology and historical biogeography of Australian plants, particularly Eucalypts and flora, and in science educat ...

and two of these are recognised by the

Australian Plant Census The Australian Plant Census (APC) provides an online interface to currently accepted, published, scientific names of the vascular flora of Australia, as one of the output interfaces of the national government Integrated Biodiversity Information Sys ...

(APC): * ''Eucalyptus diversifolia'' subsp. ''diversifolia'' has smooth bark and cup-shaped fruit less than in diameter; * ''Eucalyptus diversifolia'' subsp. ''hesperia'' has a short skirt of rough bark at the base and fruit that is usually smaller than in subspecies ''diversifolia''. ''Eucalyptus diversifolia'' subsp. ''megacarpa'' is regarded as a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of ''E. diversifolia'' subsp. ''diversifolia'' by the APC but is an accepted subspecies in Victoria and has fruit that is in diameter. This species is part of the ''Eucalyptus'' subgenus series ''Diversiformae'', a group of mallees that all have adult leaves held erect, buds with a single unscarred operculum and pyramidal seeds. The other species in this series include '' E. erectifolia'', '' E. platydisca'', '' E. pachyloma'', '' E. todtiana'', '' E. lateritica'', '' E. dolorosa'' and '' E. buprestium''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

(''diversifolia'') is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

words ''diversus'' meaning "different", or "unlike" and ''folium'' meaning "leaf", referring to the difference between the old and young leaves, but this is a characteristic of the genus ''Eucalyptus''.

Distribution

Soap mallee grows in soils derived from

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

, often on exposed headlands. Subspecies ''diversifolia'' is found on the Eyre and lower

Yorke Peninsula The Yorke Peninsula, known as Guuranda by the original inhabitants, the Narungga people, is a peninsula located northwest and west of Adelaide in South Australia, between Spencer Gulf on the west and Gulf St Vincent on the east. The peninsula ...

s, on

Kangaroo Island Kangaroo Island (, ) is Australia's third-largest island, after Tasmania and Melville Island, Northern Territory, Melville Island. It lies in the state of South Australia, southwest of Adelaide. Its closest point to the mainland is Snapper Poi ...

in South Australia and eastwards to the

Cape Nelson State Park The Cape Nelson State Park, near Portland on Victoria's southwest coast is a state park. Attractions include a clifftop walk and a visit to the Cape Nelson lighthouse. The lighthouse was completed in 1884 and today offers accommodation in the L ...

with an isolated population near

Aireys Inlet Aireys Inlet is a town located on the Great Ocean Road, southwest of Melbourne, Victoria, Australia. Aireys Inlet is located between Anglesea and Lorne, and joined with Fairhaven, Moggs Creek, and Eastern View to the west. Many surfers holi ...

in Victoria, but it is absent from the

Nullarbor Plain The Nullarbor Plain ( ; Latin: feminine of 'no' and 'tree') is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its no ...

in far western South Australia. Subspecies ''hesperia'' occurs west of the Nullarbor Plain between Eucla, Caiguna, Cocklebiddy and

Madura is an list of islands of Indonesia, Indonesian island off the northeastern coast of Java. The island comprises an area of approximately (administratively including various smaller islands to the east, southeast and north that are administratively ...

Uses

This species is able to produce large amounts of

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

, making per hectare per year. In wheatbelt regions it is also beneficial as the tree will reduce

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

, give shade to stock, act as a windbreak and reduce

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

Gallery

File:Eucalyptus diversifolia - adult leaves.jpg, adult leaves File:Eucalyptus diversifolia buds.jpg, flower buds and flowers File:Eucalyptus diversifolia fruit.jpg, buds and fruit File:Eucalyptus diversifolia - fruit.jpg, open fruit File:Eucalyptus diversifolia - trunk bark.jpg, bark

References