Psoralea pentaphylla L.
Lotodes pentaphylla (L.) Kuntze
Pediomelum trinervatum Rydb.
Psoralea trinervata (Rydb.) Standl.
Common Name: Small Indian Breadroot
Pediomelum pentaphyllum is a herbaceous perennial plant growing from a subglobose tuber 15 - 20mm thick. The plant branches at the base; the stems are trailing to decumbent, around 10 - 30cm long.
The plant is harvested from the wild for local use as a medicine.
Although no specific mention of toxicity for this species has been found, at least some members of this genus are known to contain furanocoumarins, particularly psoralen and angelicin. These compounds can be found in low concentrations in many common foods including citrus fruirs, celery, parsley and parsnips. Ingestion or skin application of these compounds in larger quantities can cause skin photosensitization followed by hyperpigmentation[
Southern N. America - Arizona to Texas, through northern and central Mexico to Jalisco and Guanajuato
Desert grassland or desert scrub among creosote bush or mesquite in sandy or gravelly loam soils; at elevations from 1,350 - 2,000 metres
Pediomelum pentaphyllum is found from the warm temperate regions of southern USA to the tropical zone of central Mexico. It can be found growing in semi-arid areas in the north of its range, where it can experience frosts, to tropical deciduous forests in the south, where mean annual rainfall can be around 2,050mm[
Species in this genus generally require a well-drained soil in a sunny position, succeeding in most soils[
Plants are very intolerant of root disturbance, they are best planted out into their permanent positions whilst still small[
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[
The root is antiperiodic, antipyretic and astringent. It used in the treatment of high blood pressure, malaria and fevers, and is chewed as a remedy for tooth decay[
A decoction of the plant (part not specified) is used in the treatment of stomach disorders[
The stem bark is astringent and has been used to treat diarrhoea in children[
The roots contain the alkaloid psoralin, an essential oil, an acid resin and colouring matter[
The roots have been shown to be an effective febrifuge[
Pre-soak the seed for 24 hours in warm water, ensuring the seed has swollen before sowing.
Sowing outdoors in situ is probably the safest way to start this plant off. If doing this, and seed stocks are in short supply, sow the seed in early spring around 5 - 10mm deep and place a moderate sized clear glass or plastic jar over the seed to help protect it from predation. Remove the jar once the plant is growing well.
Alternatively, sow the soaked seed in early to mid spring in a greenhouse. Either sow the seed in individual pots or pot up the young seedlings as soon as possible in order to avoid root disturbance. Grow them on in the pots until planting out in their final positions. It is usually impossible to transplant this species without fatal damage to the root[
Division in spring. With great care since the plant resents root disturbance. It is virtually impossible to divide this species successfully[