About Eucalyptus diversifolia Bonpl.
Eucalyptus diversifolia Bonpl., commonly called soap mallee, is a mallee that typically grows 0.5 to 8 meters (1 foot 8 inches to 26 feet 3 inches) tall, and forms a woody lignotuber. It has smooth bark that is mostly cream-coloured and grey. Young plants and coppice regrowth have sessile, egg-shaped to elliptic leaves arranged in opposite pairs, that measure 40 to 75 millimeters (1.6 to 3.0 inches) long and 10 to 25 millimeters (0.39 to 0.98 inches) wide. Adult leaves are arranged alternately, are the same shade of olive-green or bluish-green on both sides, and are lance-shaped, measuring 55 to 100 millimeters (2.2 to 3.9 inches) long and 10 to 22 millimeters (0.39 to 0.87 inches) wide, attached to a 12 to 18 millimeter (0.47 to 0.71 inch) long petiole. Flower buds are arranged in groups of seven, nine or eleven in leaf axils on an unbranched peduncle 5 to 20 millimeters (0.20 to 0.79 inches) long, with individual buds attached to a pedicel 1 to 6 millimeters (0.039 to 0.236 inches) long. Mature buds are diamond-shaped, 5 to 12 millimeters (0.20 to 0.47 inches) long and 4 to 7 millimeters (0.16 to 0.28 inches) wide, with a conical to beaked operculum. Flowering occurs between July and September, or between December and January, and the flowers are white to cream-yellow. The fruit is a woody, cup-shaped capsule 5 to 11 millimeters (0.20 to 0.43 inches) long and 8 to 11 millimeters (0.31 to 0.43 inches) wide. It is either sessile or borne on a pedicel up to 7 millimeters (0.28 inches) long, with valves that sit approximately level with the rim of the capsule. The seeds are smooth, glossy brown, and pyramidal in shape. Soap mallee grows in soils derived from limestone, most often on exposed headlands. Subspecies diversifolia occurs on the Eyre and lower Yorke Peninsulas, and on Kangaroo Island in South Australia; it ranges eastwards to Cape Nelson State Park in Victoria, with an isolated population near Aireys Inlet in Victoria. It is not found on the Nullarbor Plain in far western South Australia. Subspecies hesperia occurs west of the Nullarbor Plain, between the locations of Eucla, Caiguna, Cocklebiddy and Madura. This species produces large amounts of biomass, yielding 10 to 20 metric tons (11 to 22 short tons) per hectare per year. In wheatbelt regions, it provides multiple benefits: it reduces soil salinity, provides shade for livestock, acts as a windbreak, and reduces erosion.
