Phaseolus crotalarioides Benth.
Phaseolus hastaefolius Benth.
Phaseolus hastifolius Benth.
Phaseolus lathyroides L.
Phaseolus maritimus Benth.
Phaseolus psoraleoides Wight & Arn.
Phaseolus semierectus L.
Phaseolus strictus Braun & Bouché
Common Name: Phasey Beans
Macroptilium lathyroides is an annual to short-lived perennial plant growing up to 150cm tall. The habit can range from erectly branching to sometimes trailing and, especially in the shade, sometimes twining into other plants[
The plant is sometimes harvested from the wild for local use as a food. It can be grown as a green manure and cover crop.
Widespread in the American tropics from Argentina north through S. America (but not Brazil) and C. America to Mexico; Caribbean
Wet places along roadsides, on waste land, in open fields, pastures, in open situations along streams and rivers[
]. Open fields or slopes, in wet or dry places, often a weed about dwellings in tropical lowlands[
|Other Uses Rating||
|Cultivation Status||Cultivated, Wild
Macroptilium lathyroides is found from low elevations in the subtropics up to elevations of 2,000 metres in the tropics. It is adapted to a wide mean annual rainfall range from 500 - 3,000 mm. The optimum day/night temperature for growth is 35/20°c. Plants can survive light frosts but are killed by heavier frosts, though they have usually produced their seed before this[
Prefers a sunny position but is tolerant of light to moderate shade[
]. The plant is adapted to acid and alkaline soils, and a wide range of soil textures from sand (given reliable rainfall) to heavy clay. It can tolerate moderate salinity. It grows well in a freely draining soil, but is also tolerant of waterlogging and poor drainage and frequently grows in drains along the edges of roads[
]. Prefers a pH in the range 6 - 7, but can tolerate 5 - 8[
The seed is ejected forcibly by the seedpod shattering when it is fully ripe and can be thrown several metres[
]. Although it has become widely naturalised, it is rarely considered a serious weed[
]. The plant is considered to be invasive in several Pacific Islands and in northern Australia[
The plant survives drought by shedding its seed, which can lie dormant in the soil until wet weather returns[
This species has a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[
Seed - cooked[
]. The seedpods are around 5 - 12cm long and 2 - 3mm wide, containing up to 20 oblong seeds (exceptionally 30) around 3mm long[
The plant fixes atmospheric nitrogen very effectively and can be used as a cover crop and green manure[
Like many species within the family Fabaceae, once they have ripened and dried the seeds of this species may benefit from scarification before sowing in order to speed up and improve germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing[
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