Oval or elliptical

A perennial with a deep taproot, numerous lateral roots and a dense crown of weak stems forming rather flat clumps. Leaves are alternate, soft, 4 to 5 cm long and sparsely covered with long greyish hairs. Flowers are about 3 mm across, lilac or purple coloured with tiny yellow centres. They are closely packed in rows along one side of the spike which is rolled back from the tip. The spikes are often in pairs at the ends of the branches.

Blue Heliotrope is found in south-eastern Queensland and NSW. It is not a major pest of cane fields but is capable of regrowing from both cut off tap-roots and lateral roots.

64. Indian heliotrope

Heliotropium indicum

A stout, erect, annual herb which is covered with white hairs. Leaves are dull, dark green above, paler beneath and usually wrinkled. They are tapered at both ends and 5 to 15 cm long and 3 to 10 cm wide. Flowers are 3 mm across and carried on the outside of curled spikes which straighten and extend to 15 cm. Petals are white to blue leading into a yellow throat.

Indian Heliotrope has become naturalised in the central and southern districts. Although it is distributed widely it only occurs sporadically and does not appear to be aggressive.

65. Knobweed

Hyptis capitata

A perennial with a short rootstock and several erect stems growing 0.6 to 2.5 m high. The stems are widely-branched, square and green in colour. Leaves are opposite, widely spaced along the stems, bright green and 12 cm long and 5 cm wide. They taper at both ends and the margins are irregularly toothed. Flowers are white and small in compact knob-shaped heads. They are about 15 mm long and on long stalks up to 5 cm long located in the forks of the leaves. Seeds are small, black and when ripe they rattle when the heads are shaken.

Knobweed is common in northern districts. It is generally found on headlands and in poorly cultivated areas but also infests cane fields. When cane is fired the weed burns and does not cause problems during harvesting.

66. Small square weed

Mitracarpus hirtus

An annual herb, with square stems and growing to 60 cm. Branching stems grow from the leaf joints. Leaves are opposite, oval-shaped and covered with short hairs and have impressed veins on the upper surface. Flowers are white and in tight clusters surrounding the stem in the leaf joints.

Small Square Weed is principally a weed of the northern cane areas but has been recorded in the Moreton area as a weed of waste areas. Also (misleadingly) called Clover.

67. Ink weed

Phytolacca octandra

An erect, short-lived perennial growing to 3 m but usually much less. It has thick, reddish, smooth stems forming many branches. Leaves are shortly stalked, alternate, smooth and soft. They taper at both ends, are green above and paler beneath, 7 to 15 cm long and 2 to 6 cm wide. Flowers are greenish-white and in dense spikes at the top of the plant. Fruits are about 5 to 8 mm across, fleshy, purplish-red when ripe and have red juice. Seeds are hard and usually 6 to 8 are found in each fruit.

Ink Weed is widespread but is not usually a serious weed of cane fields. It grows on recently cleared and on cultivated ground, particularly in rain-forest areas.

68. White-eye

Richardia brasiliensis

A hairy, pale green, semi-erect, clump-forming perennial. Leaves are broad, oval, pointed at the tip and about 4 cm long and 3 cm wide. They taper to a short stalk and are expanded at the base into a stem-clasping outgrowth carrying a number of short, stiff bristles. Flowers are about 2 mm across, small, white and clustered in the leaf forks. These open outwards from the centre of the cluster.

White-eye is widespread and common. It is generally found on the drier, sandier soils and will compete with young cane if permitted to grow unchecked. It is a familiar weed of roadsides and headlands.

69. Common sida

Hyptis sauveolens

A tough, woody plant with a strong taproot, growing to 2 m but usually 1 m or less. Stems are twiggy and have green bark. Leaves are alternate, dull green on top and grey-green below. They are lance or diamond-shaped, 2 to 8 cm long and serrated towards the ends. Flowers are pale yellow, on slender stalks and seeds are contained in a 10 part cup, each cup having 2 sharp points at the top.

Common Sida is widespread and common. It is a minor weed of headlands and cultivated areas and can occasionally be a problem in cane fields. Also called Sida Retusa or Paddy's Lucerne.

70. Blackberry nightshade

Solanum americanum

An erect annual or short-lived perennial herb that grows from 30 to 100 cm. Leaves are dark green or purple-green, alternate, soft and with wavy margins. They are 3 to 10 cm long, tapered towards the tip and broadest at the base. The leaf stalks are narrowly-winged and 1 to 4 cm long. Flowers are star-shaped, white to purple-tinted and 6 to 8 mm across with a central ring of 5 bright yellow stamens. Flowers are individually stalked and carried in groups between the leaf joints. The berries are globular, succulent and green, turning glossy black when ripe.

Blackberry Nightshade is widespread and common. It germinates readily following cultivation and is a familiar weed of young plant cane. A strong root system makes it difficult to control by cultivation.

71. Wild tobacco tree

Solanum mautitianum

A large, spreading shrub or a small tree often 3 to 4 m high with branched stems. Leaves are up to 30 cm long and 10 cm wide. They are yellowish-green above, paler beneath and thickly covered with dense, felty hairs giving them a velvety feel. They are tapered at both ends with short, stout stalks and two ear-shaped, leaf-like stipules at the leaf base. Flowers are lavender blue and are in dense, flat-topped bunches at the ends of the branches. The bunches are 15 cm across and individual flowers are about 12 mm across. Fruits are round and yellow when ripe.

Wild Tobacco Tree is a common weed of roadsides, creek banks and headlands.

72. Devil's fig

Solanum torvum

An open, branched shrub growing to 3 m. Stems have scattered, stout, broad-based, yellowish thorns. Leaves are large, up to 20 cm long and 10 cm across, often appearing to be in pairs with a small leaf opposite a large leaf. Leaves are dark green above, pale green beneath, thickly felted with soft hairs and with prickles on both surfaces. Flowers are in stalked bunches arising from the stems between the leaves. They are white, star-shaped and about 1.5 cm across with a central cone of yellow stamens.

Devil's Fig is widespread and common, especially on recently cleared land. It favours the higher rainfall and northern districts.

73. Borerria

Spermacoce latifolia

Borreria is a sprawling herb with weak, wiry, four-angled stems which can root at the joints. The plant can scramble to a height of 2.5 m in dense vegetation. Leaves are opposite, broadly elliptical, pointed at the tip and up to 8 cm long and 4 cm wide. They are conspicuously veined, somewhat stiff-hairy above, softly-hairy beneath and tapering at the base into short leaf stalks. Flowers are small, white to pale blue, and in dense clusters in the leaf forks.

Borreria is only found in the northern districts where it is wide-spread. It grows vigorously smothering young cane and later preventing satisfactory burning of the crop. Also called Square Weed.

74. Snake weeds

Stachytarpheta spp.

Clump forming perennials with woody rootstocks and tough, branched stems. The leaves are opposite, oval and tapering at the base into a short stalk. The leaves of Dark Blue Snake Weed (S. urticifolia) are more sharply serrated, wrinkled and more deeply veined than those of Blue Snake Weed (S. jamaicensis). Flower spikes are stiff, up to 50 cm long and about 5 mm wide. Individual flowers have a slender tube and five petals. The flower colour varies from blue to dark violet or purple in the two species.

Snake Weeds are widespread, common and found on neglected pasture, roadsides, headlands and occasionally in young cane. Dark Blue Snake Weed (on the right) is predominant in northern districts and Blue Snake Weed (on the left) in the south.

75. Chickweed

Stellaria media

A semi-erect to sprawling annual with soft, weak stems which root at the joints where they contact the ground. The upper leaves are without stalks; the lower ones on stalks 1 to 2 cm long. Leaves are opposite, pale green and soft. They are elliptical, about 2 cm long and 1 cm wide. Flowers are small, white and in groups on slender stalks, mainly at the end of stems. Fruit capsules are papery, about 5 mm long and split at the top to release reddish-brown seeds.

Chickweed has become naturalised in many areas. It favours the southern districts where it grows and flowers during winter. It is a common weed of gardens but is also found on the margins of canefields and on headlands and roadsides.

76. Cinderella weed

Synedrella nodiflora

An erect, rough and slightly hairy, annual herb growing to 1 m. The leaves are opposite, elliptical and serrated with shallow, rounded teeth. They are 2 to 13 cm long, pointed at the tip and taper at the base into a short, winged leaf stalk. Flower heads are up to 1 cm wide and are clustered at the ends of branches or in the upper leaf forks. They consist of green scales on the outside and pointed, pale, chaffy scales on the inside with a few bright yellow 'petals'. The seeds are black, about 4 mm long.

Cinderella Weed is widespread but favours the northern districts. It grows thickly on land cleared of rainforest and on disturbed sites such as roadsides and wasteland. It usually does not persist in cultivated areas.