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Indian breadroot, large Indian breadroot, prairie turnip

Rydberg's Indian breadroot, Rydberg's scurfpea

Habit Herbs usually caulescent, rarely subacaulescent to acaulescent, to 50 cm, eglandular and pubescent throughout. Herbs acaulescent, to 20 cm, mostly glandular and pubescent throughout.
Stems

erect, usually unbranched, sometimes branched basally, leaves dispersed along stem and arising nearly perpendicular to it;

pseudoscapes 0.5–2 cm;

cataphylls 0.5–15 mm, striate.

absent, leaves clustered;

pseudoscapes 5–7 cm (when present);

cataphylls 7–9 mm, striate, clustered apically.

Leaves

palmately (3–)5-foliolate;

stipules persistent, broadly lanceolate proximally to linear-lanceolate distally, 10–20 × 2–8 mm, stramineous basally, eglandular, glabrate to sparsely pubescent, hairs semi-erect;

petiole not jointed basally, (2–)30–100(–150) mm;

petiolules 1.5–4 mm;

leaflet blades elliptic to oblanceolate, 2–4(–6) × 0.7–2.3 cm, base attenuate to cuneate, apex broadly acute to rounded or retuse, surfaces abaxially pubescent, adaxially glabrate except on midvein.

pinnately 3-foliolate;

stipules persistent, lanceolate to oblanceolate-oblong, 5–7(–12) × 2.5–3 mm, stramineous, eglandular, glabrous;

petiole swollen proximally or not, not jointed, (30–)50–120 mm;

petiolules 2 mm;

leaflet blades orbiculate to obovate-trullate, lateral 2 usually asymmetrical, 1.5–2.5(–3.2) × 1–2.4 cm, base broadly cuneate or truncate, apex broadly acute, surfaces abaxially white-pubescent, adaxially white-hirsute along veins and margins.

Inflorescences

persistent (not disjointing at base of peduncle in fruit), elliptic to oblong;

rachis 1.6–7 cm, elongating slightly in fruit, nodes (6–)8–15, (2 or)3 flowers per node;

bracts persistent, oblanceolate to elliptic, 5–15 × (0.5–)4–9 mm, glabrate to sparsely pubescent, hairs semi-erect.

disjointing in age at peduncle base, ovate to elliptic;

rachis 1.4–1.6 cm, crowded, nodes 4–7, 3 flowers per node;

bracts persistent, caudate-lanceolate, 5–8 × 2–3.5 mm, pubescent throughout or only at apex.

Peduncles

(0.5–)5–12(–15) cm, shorter than subtending petiole, pilose.

2–10 cm, shorter than subtending petiole, glabrous proximally, pubescent distally.

Pedicels

1–3 mm.

1–3 mm.

Flowers

12–20 mm;

calyx strongly gibbous-campanulate in fruit, 13–16 mm abaxially, 12–14 mm adaxially, eglandular, pubescent;

tube 5–6 mm;

lobes linear or linear-lanceolate to elliptic, abaxial 7.5–10 × 2–2.5 mm, adaxial 4–7 × 1–1.5 mm;

corolla violet to blue-purple, banner sometimes paler, oblanceolate, 17–18 × 6 mm with claw 7–8 mm, wings 15–16.5 × 3–3.5 mm with claw 6–6.5 mm, keel 12–12.5 × 3 mm with claw 6–6.5 mm;

filaments 11–14 mm;

anthers elliptic, 0.5 mm;

ovary pubescent apically, style glabrous apically.

12–20 mm;

calyx gibbous-campanulate in fruit, 10–15(–17) mm, pubescent throughout or teeth only;

tube 5–7 mm;

lobes linear or linear-lanceolate, abaxial 8–8.5 × 1–1.5 mm, adaxial 6–7.5 × 0.5–1 mm;

corolla white and blue-purple, banner white to pale purple, oblanceolate, 15–17 × 6–7 mm with claw 4.5–5.5 mm, wings blue-purple, 12–14 × 2.5–3 mm with claw 5.5–6.5 mm, keel dark purple, 14–16 × 2.5–3 mm with claw 8.5 mm;

filaments 16 mm;

anthers elliptic, 0.7 mm;

ovary glabrous, style glabrous.

Legumes

oblong, 4–6 × 2.5–3.5 mm, eglandular, pubescent, beak 9–13(–16) mm, exserted beyond calyx.

oblong-ellipsoid, 5–7 × 3.5–4 mm, eglandular, pubescent apically, beak 4–5 mm, about as long as calyx.

Seed

brown, reniform, 4 × 3 mm, somewhat rugose.

black, ellipsoid-reniform, 3.5–6 × 2.5–4 mm.

2n

= 22.

Pediomelum esculentum

Pediomelum humile

Phenology Flowering late spring–summer. Flowering spring.
Habitat Prairies, grasslands, open pine woodlands. Shallow, rocky clay or limestone soils, shortgrass prairies, shrublands.
Elevation 500–2000 m. (1600–6600 ft.) 700–2000 m. (2300–6600 ft.)
Distribution
from FNA
AR; CO; IA; IL; KS; MN; MO; MT; ND; NE; NM; OK; SD; TX; WI; WY; AB; MB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
TX; Mexico (Coahuila)
[BONAP county map]
Discussion

Pediomelum esculentum was once one of the main sources of starch for Native American tribes of the Great Plains, eaten fresh, boiled, dried, or ground into flour and used as a thickening agent. Use of the root for food and barter was documented by Lewis and Clark on their historic expedition across the United States (Mer. Lewis and W. Clark 2003).

Pediomelum esculentum ranges in morphology from strongly caulescent to acaulescent with no apparent geographical structuring in this most widespread species. J. W. Grimes (1990) placed this species in subg. Pediomelum due to its persistent inflorescences. Molecular phylogenetic and network analyses suggest a split affinity for P. esculentum between both subgenera, suggesting that this may be an intermediate form and bridge between his subgenera or the groupings suggested by D. J. Ockendon (1965) based on habit—groupings somewhat supported by molecular phylogenies (A. N. Egan and K. A. Crandall 2008, 2008b).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Pediomelum humile, historically known from along the Rio Grande in Texas (Val Verde County) and Mexico, is very rare and on the verge of extinction. Several known populations have been destroyed by urban development in the recent past. The few populations in existence today are located near Del Rio and are all in danger of extirpation due to human influences. Pediomelum humile is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Psoralea humilis (Rydberg) J. F. Macbride 1922, an illegitimate name (not Miller 1768), pertains here.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Pediomelum Fabaceae > subfam. Faboideae > Pediomelum
Sibling taxa
P. argophyllum, P. aromaticum, P. californicum, P. canescens, P. castoreum, P. cuspidatum, P. cyphocalyx, P. digitatum, P. epipsilum, P. humile, P. hypogaeum, P. latestipulatum, P. linearifolium, P. megalanthum, P. mephiticum, P. palmeri, P. pariense, P. pentaphyllum, P. piedmontanum, P. reverchonii, P. rhombifolium, P. subacaule, P. tenuiflorum, P. verdiense
P. argophyllum, P. aromaticum, P. californicum, P. canescens, P. castoreum, P. cuspidatum, P. cyphocalyx, P. digitatum, P. epipsilum, P. esculentum, P. hypogaeum, P. latestipulatum, P. linearifolium, P. megalanthum, P. mephiticum, P. palmeri, P. pariense, P. pentaphyllum, P. piedmontanum, P. reverchonii, P. rhombifolium, P. subacaule, P. tenuiflorum, P. verdiense
Synonyms Psoralea esculenta Psoralea rydbergii
Name authority (Pursh) Rydberg in N. L. Britton et al.: N. Amer. Fl. 24: 20. (1919) Rydberg in N. L. Britton et al.: N. Amer. Fl. 24: 24. (1919)
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