Fabaceae : Pediomelum esculentum
Files
Family Name
Fabaceae
Common Name
Prairie turnip, Breadroot scurf-pea, Indian breadroot
Native American Name
Dakota: Tipsi, Tipsina; Lakota: thíŋpsila
Description
Pediomelum esculentum is a perennial herb with a tuberous-thickened root, 4-10 cm below ground and with 1-3 caudices extending to the soil surface, producing 1-3 simple or rarely branched stems, 8 to 30 cm in height and covered with a dense pubescence. The alternate leaves are palmately compound with 5 leaflets attached to a petiole that is 5-10 cm long, with stipules 1-2 cm long. The leaflets are elliptic to ovate, 2–4 cm long, 7-18 mm wide, narrowing at the base, rounded, blunt or pointed at the tip. The upper surface is usually nearly smooth, and the lower surfaces are covered in flattened hairs. The inflorescences are axillary spike-like racemes, 5–12 cm long including the peduncle, and the spikes 2-2.5 cm wide. The calyx tube is 5-6.5 mm long, with 5 teeth, the upper 4 are 5-7.5 mm long, the middle 2 partially united, and the lower-most tooth 6-8 mm long. The papilionaceous corolla is blue with clawed (constricted at the base) petals, the petals beyond the claws measure: banner 9-13 mm, wings 9-13 mm and the keel 4-5 mm long. The fruit is an ovoid, single-seeded legume, 5-7 mm long, enclosed in the calyx. Prairie turnips bloom from May into July in prairies, open woodlands, on hillsides and in stream valleys throughout South Dakota.
Synonym: Psoralea esculenta
Horticulture Notes
Seed Collection: Collect seed in July when the turn dark in color and begin to be released. Bagging the seedheads with a net bag improves the harvest.
Germination: Like many legumes the seedcoat is impermeable. Scarification with sandpaper of chipping the seedcoat with the point of a small, sharp knife will ensure good germination. Fall planting of untreated seeds will provide staggered germination over the next couple of years.
Soils: Well drained sandy or loamy soils are best, if harvesting root is anticipated.
Light: Full sun
Water: Prefers drier conditions once established.
Additional Notes
Prairie turnip is an important food source for peoples of many of the plain’s tribes. It is easy to grow in a native plant garden and begins producing roots large enough to harvest after about 4 years. The plants attract native bees and butterflies, and their wooly foliage adds texture to the garden. Traditionally the roots are harvested when plant is in the flowering to fruiting stage. Like P. argophyllum, the tops break off when the seeds are ripe and are blown like tumbleweeds, spreading their seeds.