Lasia spinosa THW. (Araceae)
Vernacular name: phak naam
Common name: lasia (English)
Herb, 40-120 cm high, leaf stalk thorny. Leaves rosette, simple, lanceolate, sagittate, or pinnatipartite, thorny along the veins, 30-45 cm long, up to 25 cm wide; petiole 20-50 cm long. Spathe twisted, opening only at the bases, 15-30 cm long, brown or purple; spadix cylindrical, up to 6-8 cm long and 3-3.5 cm wide; peduncle thorny. Berryobovoid, muricate at the top, 1 cm long; seed 5 mm long, 3.5 mm wide.
Common in moist, shaded areas along rivers in evergreen forest, widespread throughout the country. The plants are normally collected from natural habitat, it is occasionally grown for family consumption.
The young leaves are edible, but must be cooked or fermented to neutralize the hydrocyanic acid. They are eaten with, nam phrik plaa raa (chilli sauce with fermented fish), cooked in hot and sour soup or simply fried.
Both the rhizomes and leave are expectorants. The latter also help ease stomachaches. The roots are boiled and the water used to bath newborn babies.
Caution: This plant should not be eaten raw due to highly toxic prussic acid which is hydrolyzed to form the fatal hydrocyanic acid.