Spyridium is a genus of roughly thirty species of flowering shrubs and subshrubs in the family Rhamnaceae (order Rosales), endemic to Australia. The genus was first formally described in 1837 by the Austrian botanist Eduard Fenzl, based on material collected in south-western Australia; the first species formally named was Spyridium eriocephalum.
Plants in the genus are typically small shrubs or subshrubs, rarely exceeding 1 metre in height. Young branchlets are covered in white or rusty woolly hairs, and the alternate leaves are usually small with papery brown stipules at their base. The flowers are highly distinctive: they are sessile (lacking individual stalks), densely covered in white woolly hairs, and grouped into small composite heads subtended by small persistent brown bracts. These heads are themselves arranged in corymbose cymes. Each flower is bisexual and possesses five sepals, five hooded petals that typically enclose the anthers, and a disc that is either annular or divided into five glands. The fruit is a capsule enclosed within the persistent hypanthium and topped by the remaining sepals.
Species of Spyridium are distributed across most of Australia, occurring in New South Wales, Victoria, Tasmania, South Australia, and Western Australia, but are absent from Queensland. The name Spyridium derives from the Greek word for "a small basket", alluding to the bracts that surround and cup the compact flower clusters.
Etymology
The genus name Spyridium derives from the Greek word for "a small basket", a reference to the brown bracts that surround and enclose the compact clusters of flowers. The genus was formally established in 1837 by Eduard Fenzl, with Spyridium eriocephalum as the founding species.
Distribution
Spyridium is endemic to Australia. Its roughly thirty species are distributed across New South Wales, Victoria, Tasmania, South Australia, and Western Australia; the genus is notably absent from Queensland. Most species occur in heathlands, dry sclerophyll forests, and mallee scrubland on well-drained, often nutrient-poor soils.
Taxonomy
The genus was first formally described in 1837 by Eduard Fenzl in Stephan Endlicher's Enumeratio plantarum quas in Novae Hollandiae ora austro-occidentali ad fluvium Cygnorum et in sinu Regis Georgii collegit Carolus Liber Baro de Hügel. It is placed in the family Rhamnaceae, order Rosales. The Australian Plant Census is the primary authority for accepted species names within the genus.
