phasey bean

Macroptilium lathyroides

Phasey bean (Macroptilium lathyroides) normally has an upright habit and bright red or reddish-purple flowers. Its leaflets are never lobed and are relatively narrow.

Common names 
Also known as: phasey bean, cow pea, cowpea, pea bean, wild bean, wild bushbean,
Flowering time 
Year round
Native to Mexico, Central America, the Caribbean and South America.
Council declaration 
SIL – Special Investigation List
Known distribution 

Widely naturalised in northern Australia. It is most common in north-eastern New South Wales, eastern Queensland and the northern parts of the Northern Territory.


A weed of disturbed sites, waste areas, roadsides, crops and gardens.


A long-lived (i.e. perennial) woody herbaceous plant with upright (i.e. erect) stmes growing up to 1 m tall. Older plants may occasionally develop climbing or twining branches towards their tips if the plant is growing amongst taller vegetation.

Impact and control methods 

Phasey bean (Macroptilium lathyroides) is regarded as an environmental weed in Queensland and the Northern Territory. This species was introduced and planted as a pasture legume, but it has escaped cultivation and is now a weed of roadsides, disturbed sites, waste areas, gardens, pastures, crops and natural vegetation (i.e. riverbanks, riparian areas, grasslands and open woodlands).

Stem and leaves 

"The short-lived upright (i.e. erect) stems are produced from a long-lived rootstock. These stems are shortly-hairy (i.e. appressed pubescent).

The alternately arranged leaves are once-compound with three leaflets (i.e. trifoliolate). These leaves are borne on stalks (i.e. petioles) 1-5 cm long and there is a pair of small (5-6 mm long), elongated, leafy structures (i.e. stipules) at the base of each the leaf stalks. The leaflets (3-8 cm long and 1-3.5 cm wide) are narrowly oval (i.e. elliptic) or narrowly egg-shaped in outline (i.e. ovate) with entire margins. They have hairless (i.e. glabrous) upper surfaces and sparsely hairy (i.e. pilose) undersides."

Flowers and fruits 

"The pea-shaped flowers (about 15 mm long) are bright red or purplish-red (very rarely white) and are borne towards the ends of stalks (i.e. peduncles) that are up to 50 cm long. Flowering occurs throughout the year.

The elongated pods are narrow (8-10 cm long and 2-3.5 mm wide) and covered with close-lying (i.e. appressed) hairs. They turn from green to brown in colour as they mature and become strongly twisted. Seeds (about 3.5 mm long and 3 mm wide) are brown or mottled brown and black in colour and have a slightly pitted surface texture."

Similar species 

"Phasey bean (Macroptilium lathyroides) is similar to siratro (Macroptilium atropurpureum ), but the two species can be best distinguished by the following differences:
phasey bean (Macroptilium lathyroides) normally has an upright habit and bright red or reddish-purple flowers. Its leaflets are never lobed and are relatively narrow.

siratro (Macroptilium atropurpureum ) is normally has a creeping or climbing habit and its flowers are darker reddish-purple or blackish-purple in colour. Its leaflets are often slightly lobed and are relatively broad."