Pediomelum esculentum |
Pediomelum piedmontanum |
|
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Indian breadroot, large Indian breadroot, prairie turnip |
Dixie Mountain breadroot, Piedmont breadroot |
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Habit | Herbs usually caulescent, rarely subacaulescent to acaulescent, to 50 cm, eglandular and pubescent throughout. | Herbs caulescent, 50–80(–100) cm, mostly glandular throughout and strigose. |
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. |
usually 1, rarely 2, erect, unbranched proximally to much branched distally, leaves dispersed along distal branches; pseudoscapes 0; cataphylls 6–10 mm. |
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. |
palmately 3(–5)-foliolate; stipules persistent, mostly linear-lanceolate, 7–12 × 6.5–9 mm, sparsely strigose; petiole, when present, not swollen or jointed basally, slightly canaliculate, (0 or)2–2.5(–4) mm, usually shorter than petiolules, sparsely strigose; petiolules often adnate to leaf spur, 1.8–3 mm; leaflet blades narrowly to broadly elliptic, (1–)1.2–5(–5.5) × (0.4–)0.6–2.7 cm, base cuneate, apex rounded to shallowly retuse and often mucronate, surfaces sparsely strigose. |
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. |
persistent, crowded, rachis usually concealed, usually elliptic to oblong, rarely ovate; rachis (1–)2–5(–5.5) cm, nodes (4–)6–13(–15), (1–)3(or 4) flowers per node; bracts persistent, broadly ovate to suborbiculate, 8–11.5 × (7–)9–10 mm, glabrous. |
Peduncles | (0.5–)5–12(–15) cm, shorter than subtending petiole, pilose. |
0.6–2.8(–3.4) cm, longer than subtending petiole, appressed-spreading pubescent. |
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. |
12.5–14 mm; calyx strongly gibbous-campanulate in fruit, 12–16 mm abaxially, (10–)12–13 mm adaxially, glandular, pilose; tube 4–5 mm; lobes linear-lanceolate, abaxial (6–)7–11(–11.5) × 1.5–3 mm, adaxial 4–8 × 1–1.5 mm; corolla violet to lavender or cream to yellowish and tinged with violet, banner broadly oblanceolate to obovate, (8.5–)10–14 × 5.5–7 mm with claw (3.5–)4.5–7 mm, wings (7–)8–12 × 2–2.5 mm with claw (3–)4–6 mm, keel (5–)6–10 × 2–2.5(–3) mm with claw (3–)4–5 mm; filaments 9.5–11 mm; anthers broadly elliptic, 0.5(–0.8) mm; ovary glabrous, style glabrous, sometimes strigulose basally. |
Legumes | oblong, 4–6 × 2.5–3.5 mm, eglandular, pubescent, beak 9–13(–16) mm, exserted beyond calyx. |
broadly ellipsoid to nearly obovoid, 6–7 × 4–4.5 mm, glabrous, dark brown-glandular on distal 1/2, beak (5–)6–8 mm, exserted beyond calyx. |
Seed | brown, reniform, 4 × 3 mm, somewhat rugose. |
gray-brown, reniform, 3.5–5 × 2.5–3.5(–4) mm. |
2n | = 22. |
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Pediomelum esculentum |
Pediomelum piedmontanum |
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Phenology | Flowering late spring–summer. | Flowering summer. |
Habitat | Prairies, grasslands, open pine woodlands. | Rocky, open areas, adjacent open woodlands. |
Elevation | 500–2000 m. (1600–6600 ft.) | 0–100 m. (0–300 ft.) |
Distribution |
AR; CO; IA; IL; KS; MN; MO; MT; ND; NE; NM; OK; SD; TX; WI; WY; AB; MB; SK
|
GA; SC |
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 piedmontanum is known from only three populations, one in Georgia and two in South Carolina, with an estimated 1000 individuals in existence. Populations are newly threatened by the recent invasion of Megacopta cribraria (the Kudzu Bug), seen inhabiting plants in South Carolina, as well as continued herbivory and damage by moths, which make this species of special conservation concern. (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 | ||
Synonyms | Psoralea esculenta | |
Name authority | (Pursh) Rydberg in N. L. Britton et al.: N. Amer. Fl. 24: 20. (1919) | J. R. Allison: M. W. Morris & A. N. Egan, Sida 22: 229, figs. 1, 2. (2006) |
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