Galinsoga parviflora Cav.
Potato weed, gallant-soldiers, small flowered galinsoga
A soft erect annual branched herb up to 60cm high.
A tough plant that will grow in sandy, loamy and clay soils. It will tolerate acidic, neutral and basic conditions and will grow in semi shade to full sun. It requires a moist soil and can be found in cultivated beds, waste places and pavements.
Stems and Leaves:
The stems are erect, branched, slender and striate (parallel ridged). The leaves are opposite, pale green and petiolate (with leaf stalk) and are lanceolate to ovate in shape. They are 1-6cm long and 0.5-4cm wide. The stems can be with or without hairs (glabrous). The leaf margins, however, are fringed with short hairs like an eyelash. The upper leaves are usually smaller, narrower and sessile (without a stalk).
Flowers and Fruit:
The flowerheads are small with centres of yellow disk/tubular florets surrounded by several (usually 5) small white ray florets. The stalk of the inflorescence is slender and hairy. The flower head is 4-7mm in diameter with 2 or 3 rows of involucral bracts. The 5 inner bracts each support a ray floret. The fruit associated with the ray florets is an achene (a dry indehiscent 1-seeded fruit) that is 2mm long, slightly hairy, with or without a pappus of short bristles. The fruit associated with the disc florets is also an achene but it is 1.8mm long, slightly hairy, with a pappus of hairy-edged scales that are 1.5mm long. Flowers mainly during summer.
Unlike other members of this family the ray florets are 3 lobed, small and separate from each other.
Sources & References
Auld BA, Meld RW (1992) 'Weeds an illustrated botanical guide to the weeds of Australia.' (Inkata Press: Melbourne)
Carolin R, Tindale MD (1993) 'Flora of the Sydney region.' (Reed: Chatswood, Australia)
Harden GJ (Ed) (2002) 'Flora of New South Wales.' (University of New South Wales Press Ltd: Sydney, Australia)
Prepared by Kylie Pethybridge, 2005
Checked by Carole Campbell, 2005
Updated by Justin KY Chu, July 2005
Checked by Dr Peter Michael, July 2005