Plant of the Month — March 2013
Astroloma sp. Tutanning (A.S. George 7779)
Astroloma acervatum is a new species recently discerned as distinct from the widespread and common Astroloma pallidum. Whilst similar in possessing flowers mostly cream or very pale yellow, and elliptic to narrowly obovate-elliptic leaves, the new species can be distinguished from A. pallidum by possessing a fire-sensitive rootstock, a prostrate and mat-forming habit often becoming raised and mounded in the centre, but always tapering to a well-defined margin at soil level, a bright green appearance with mature leaf margins conspicuously pale and hyaline, and a shorter sepal mucro.
While A. pallidum is widespread in the wetter parts of south-western Australia from Mt Lesueur in the north to the Wellstead area, east of Albany, Astroloma acervatum occurs only in the eastern Darling Range and adjacent parts of the western wheatbelt. The two are often sympatric in the same habitat across the range of A. acervatum, although there is no evidence of hybridisation between them. Although the distribution of A. acervatum is not extensive, it is known to occur in a number of Nature Reserves and National Parks and its preferred habitat is common across the species range, so no specific conservation status is currently required.
The main flowering period of A. acervatum is between July and September, although sporadic flowering apparently occurs at other times of the year, probably depending on available moisture. Fruit appears to be retained on the plants for many months. It is likely to be present for much of the year but with a peak between October and March. Interestingly, where A. acervatum and A. pallidum co-occur there is a significant difference in their flowering times, with the latter primarily flowering between October and December.
The species epithet is from the From the Latin acervatus meaning mounded or heaped, a reference to the distinctive growth habit of the species. Astroloma acervatum was recently described in our journal Nuytsia by Michael Hislop, Annette Wilson and Caroline Puente-Lelièvre, from which much of this text is transcribed. The paper also includes a number of detailed colour plates, specimen images and a key to allied species. This species was previously known under the phrase-name Astroloma sp. Tutanning (A.S. George 7779).
Photo: J. Hort
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