Galinsoga

Galinsoga parviflora

Galinsoga (Galinsoga parviflora), also known as Gallant Soldier, is an annual upright weed which grows to about 75 cm tall. The leaves up to 9 cm long, in opposite pairs, are oval, pointed, toothed and a greenish–yellow in colour. The flowers consist of central yellow disc florets, surrounded by five white ray florets which are 3 lobed at the tip. Usually in small clusters, flowers are seen October to April. Galinsoga is found in cultivated land, pasture, gardens and road-sides in the South Island, and more occasionally in the North Island.

Related Pests

Groundsel

Senecio vulgaris

Groundsel (Senecio vulgaris) is an annual weed, found throughout New Zealand. It is a common weed in arable and horticultural crops, gardens and waste areas. The erect weed grows to 50 cm tall with soft, leafy stems and distinctive yellow flowers.

Scentless Chamomile

Matricaria perforata

Scentless Chamomile (Matricaria perforata) is a bushy annual or biennial plant that grows to 60 cm and is wholly or almost scentless. It has an erect stem, with branches only from mid stem upwards. The leaves are fern like and sticky. The flowers are large, with twelve white petals, with central yellow disc florets, giving the flower a daisy-like appearance. They appear singly on stems and branches between December and March.

Found in moist disturbed areas such as roadsides, cropland, pasture, drainage ditches and waste areas. The seeds are 2 mm, dark brown with a raise edge, and each plant produces 10,000 - 200,000 seeds which germinate in shallow soil.

Wireweed

Polygonum aviculare

Wireweed (Polygonum aviculare) is a widespread annual with wiry, trailing stems that form mats up to 1 m in width. Wireweed (or wire weed) prefers to germinate in wet soils so it is problematic in winter and in spring sown crops as it can be very competitive and smother crops. Once larger than a seedling, is difficult to control, with selective herbicides in crops.