Botanical name: Parietaria judaica
Environmental Weed Special note: Asthma Weed pollen may cause asthma, conjunctivitis, rhinitis and hay fever.
Contact with plants may cause skin rashes and other allergic reactions. It is recommended that long clothing, a dust mask or half face respirator,
eye protection (goggles or glasses) and protective gloves be worn when handling this weed.
Photos: Adam Burrowes Drawing: Marita Macrae
Originating from Europe, Asthma Weed is also known as Pellitory or Sticky Weed. Asthma Weed is a many-branched perennial herb that grows up to 1 metre high. Leaves are green, soft, an oval shape with pointed ends, and are 2 cm to 8 cm long. Leaves are arranged alternately along pink or red stems.
Roots are pink or red, and woody on older plants. Flowers are very small, light green in colour, and clustered along the stems. Leaves, flowers and stems are covered with sticky hairs that will stick to skin, clothing and animal fur.
Seeds are dispersed by wind, water and by attachment to clothing and animals by sticky hairs. Seeds are also spread in soil and mud attached to shoes, tyres and machinery.
Asthma Weed is common on wasteground, in moist gullies, in and around sandstone outcrops, and as a groundcover in disturbed areas. Is also commonly found in gardens, often growing out of rock crevices, walls and cracks in cement.
Plants grow and produce seed very rapidly (within 2-3 weeks under favourable conditions). Regrowth is persistent, and plants can flower and set seed most of the year.
Manual:
See Manual Weed Control Techniques.
Chemical: Before commencing any chemical control program contact your local council's weeds officer on 9970 1369 for advice tailored to your situation.
Dept of Primary Industries - Agnote. Pellitory.
Source: Pittwater Council