Boggabri

Chenopodium carinatum R. Br.

Family: Chenopodiaceae.

Names:

Chenopodium is from the Neo Latin form of the Greek words Khenopous from khen, a goose, and pous, a foot and refers to the shape of the leaves in some species.
Boggabri

Other Names:

Boggabri Weed. In Queensland this refers to Amaranthus mitchellii, but in other states it is used to refer to C. carinatum also. To reduce confusion it is suggested that Boggabri be used for C. carinatum and Boggabri Weed for A. mitchellii.
Green Crumbweed
Keeled Goosefoot
Mintweed

Summary:

An aromatic, pale green, lobed leaf, summer growing, prostrate or erect annual herb to 300 mm high or wide, with a "mealy" appearance to its leaves and stems.

Description:

Cotyledons:

Two. Sparse small hairs. Oval. Pointed tip. Green on the topside, reddish underneath.

First leaves:

Small hairs. Diamond shaped. Pointed tip. Edges slightly indented or toothed.

Leaves:

Alternate, soft, green with whitish mealy appearance.
Petiole - Slender. Half as long as the blade.
Blade - Variable, oblong, lance, oval or egg-shaped. 8-20 mm long. May be lobed or have wave like indentations on the edges. Sparse short curved hairs and glandular hairs. Glandular hairs with resin droplets on the lower surface.

Stems:

Up to 300 mm long. Usually with several arising from the base. Usually branched. Minty scent. Short curved hairs and glandular hairs. Mealy appearance.

Flower head:

Compact clusters in the axils. Shorter than the leaves.

Flowers:

On no stalk or on a stalk up to 2 mm long. Egg-shaped, small, green crumb like.
Ovary - Hairless.
Perianth - 5 segments, 1 mm long, incurved, boat shaped, crested, fused near base, erect. Usually green and soft then turn white, hard and brittle at maturity. Sparsely hairy near top and on the midrib. Fully covers the seed. Hairy hooded wing broadening upwards so that it is more or less triangular in profile.
Stamens - 1 or 2.
Anthers -

Fruit:

White perianth segments cover the seed initially.

Seeds:

Small, round, reddish to black, erect sometimes keeled.

Roots:

Key Characters:

Perianth segments with a hairy, hooded wing broadening upwards so that it is more or less triangular in profile.
Minty odour.
Mealy leaves and stems.

Biology:

Life cycle:

Annual. Seeds germinate in spring and summer.

Physiology:

Reproduction:

By seed.

Flowering times:

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

Allelopathy:

Probably produces toxins that can reduce the germination and growth of crop and pasture plants.

Population Dynamics and Dispersal:

Origin and History:

Australia.

Distribution:

NSW, QLD, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Soil:

Plant Associations:

Significance:

Beneficial:

Detrimental:

Weed of pastures, stubbles and fallows, gardens, horticultural crops and disturbed areas.

Toxicity:

May contain toxic amounts of HCN and field cases are usually associated with ingestion of young plants by hungry stock.

Symptoms:

HCN poisoning.

Treatment:

Remove stock from infested areas or provide alternative feed.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Hand pull plants after elongation and before seeding in summer. Boggabri is relatively tolerant to low rates of glyphosate. For small areas use 2 L/ha Spray.Seed® plus 2 kg/ha simazine(900g/kg) plus 1% spray oil in early summer for control of existing plants and residual control of seedlings for the season. Wear protective clothing if hand spraying this mix. 500 mL/ha of atrazine(500g/L) plus 1% spray oil provides good control where its use is permitted.
In bushland areas, use 4 L/ha 2,4-DB(400g/L) or 80 mL 2,4-DB plus 25 mL wetting agent in 10 litres of water in early summer on young actively growing plants for reasonably selective control. In areas where hormone herbicides are restricted use 25 g/ha Broadstrike® plus 0.5% Uptake® or 0.5 g Broadstrike® plus 50 mL Uptake® in 10 L water on young plants. A repeat application may be required in years where summer rains induce late germinations.
Even though Boggabri is occasionally toxic, grazing usually provides reasonable control.
It often flourishes in areas that have been overgrazed, disturbed or had poor plant growth during the spring.

Herbicide resistance:

Biological Control:

Related plants:

Black Crumbweed (C. melanocarpum)
Crested Goosefoot (C. cristatum)
Desert Goosefoot (C. desertorum ssp. desertorum)
Fat Hen (C. album)
Fishweed (C. hubbardii)
Glaucous Goosefoot (C. glaucum)
Mallee Goosefoot (C. desertorum ssp. anidiophyllum)
Mexican tea (C. ambrosioides var. ambrosioides)
Nettle leaved Goosefoot (C. murale)
Nitre Goosefoot (C. nitrariaceum)
Queensland Bluebush (C. auricomum)
Scented Goosefoot (C. multifidum)
Small Crumbweed (Dysphania pumilio)
Small leaved Goosefoot (C. desertorum ssp. microphyllum)
Stinking Goosefoot (C. vulvaria)
Wormseed (C. ambrosioides var. anthelminticum)
C. curvispicatum
C. detestans
C. erosum
C. opulifolium
(C. polygonoides) Einadia polygonoides
(C. pseudomicrophyllum) C. desertorum ssp. microphyllum
(C. rhadinostachyum) Dysphania rhadinostachya
(C. trigonon) Einadia trigonos

Plants of similar appearance:

Small Crumbweed (Dysphania pumilio) is almost identical and was often considered to be the same plant up to 1933. In Boggabri weed the perianth segments are more distinctly crested and fully cover the seed. These segments have a hairy hooded wing broadening upwards so that it is more or less triangular in profile.
Crested Goosefoot (C. cristatum) is very similar but the perianth segments have a broad fringed wing with a beaked tip.
Black Crumbweed (C. melanocarpum) is similar but the perianth segments usually turn almost black at maturity and they are broader and rounder than those on Boggabri.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P149. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P289.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P147.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P24.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #297.5.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.