Blumea

Western Australia

Habit, vegetative morphology. Erect, annual or perennial, shrubs or herbs. Leaves alternate, simple. Leaf blades divided or entire, when divided pinnatifid, more or less hairy; margins serrate, or dentate. Inflorescence. Plants gynomonoecious. Unit inflorescences solitary (on axillary or terminal branches) or arranged in synflorescences, synfloresences loosely or densely corymbiform or paniculiform. Capitular involucre cylindrical to rounded (hemispheric). Capitula disciform, heterogamous, sessile or pedunculate; radially symmetrical florets spread throughout capitulum. Involucral bracts multiseriate, rather narrow, chartaceous. Receptacles flat or convex or conical (rarely slightly), alveolate, epaleate. Marginal florets. Marginal florets numerous, radially symmetrical, tubular (filiform, 2–4-lobed or 2-lipped), functionally female, multi, usually yellow or white or purple. Disc florets. Inner (central or disc) florets bisexual. Corolla tubular, usually yellow or white or purple, (4–)5 lobed, lobes shallow. Stamens of male fertile florets. Anthers minutely calcarate. Tip appendages present, truncate or obtuse. Base appendages caudate. Styles of female fertile florets. Style branches obtuse. Style branch appendages lacking. Sweeping-hairs scattered dorsally along branches. Stigmatic area in two bands fused at the summit of the style branch. Fruit. Achenes narrowly cylindric, obscurely 4- angular or terete, ribbed (ribs prominent or not so), 10 ribbed, duplex hairs present. Pappus present, uniseriate, setaceous; bristles barbellate (with patent or adpressed teeth) or smooth, bristles capillary.

Etymology. After Karel Lodewijk Blume (1796–1862), curator of the herbarium at Leiden, who specialized in the flora of the Dutch East Indies.

Additional Notes. A polyphyletic asemblage with considerable variation in micromophological characters. DNA have a copy of a manuscript treatment of Blumea by Clyde Dunlop for the Flora of Australia, compiled in or about 2000, which recognizes an undescribed species present in WA, namely Blumea psammophila Dunlop ms.

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