Geranium robertianum L.
herb Robert
Annual or biennial hairy taprooted herb, with a characteristic scent. Stems decumbent to spreading, to c. 50 cm long, lax, often red where exposed to strong light, sometimes with base thickened; internodes short and lvs rosette-like. Petioles long and slender on lower lvs, often reddish, glabrous or hairy. Lamina palmate, to c. 9 × 10 cm, broad- or triangular-ovate, usually becoming red with age; lobes 3-5, at least the terminal petiolulate, pinnately divided to varying degrees, ± appressed-hairy; ultimate segments usually mucronulate. Infl. very diffuse; fls paired; peduncles usually > pedicels; peduncles and pedicels with long- and short-stalked glands. Sepals (at anthesis) 6.5-8 mm long including apical awn, ovate, prominently 3-nerved, with hairs as on pedicels. Petals (7.5)-10-11.5 mm long, obovate-oblanceolate, pink or rose except for white margin of claw; limb = claw; apex rounded. Filaments pinkish; anthers orange. Mericarps 2.5-3 mm long, glabrous or hairy, with 4-6 transverse ridges. Seed smooth.
N.; S.: widely naturalised but commonest in the North Id.
Temperate Eurasia 1878
Modified habitats, including railway yards, gardens, roadsides, forest margins, remnant forest stands and scrub.
FL Sep-May.
Herb Robert usually grows in partial or complete shade, but on occasions plants are seen in open sites and these have thicker lvs and a generally much more pronounced redness to all vegetative parts. White-flowered plants were mentioned by Allan (1940) but no specimens have been seen. G. robertianum has been confused with the related G. purpureum and G. rubescens, but can be satisfactorily distinguished as described under those 2 spp.
