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silverleaf Indian breadroot, silverleaf scurfpea

aromatic Indian breadroot

Habit Herbs caulescent, to 100 cm, mostly glandular throughout, silvery-sericeous. Herbs caulescent, to 25 cm, mostly glandular and strigose throughout; spreading by rhizomes, often forming patches.
Stems

± erect, branched distally, branches subtended by leaves, leaves dispersed along stems, more so distally;

pseudoscapes to 10 cm (when present);

cataphylls 9–20 mm, glabrous or pubescent apically.

suberect to decumbent, branched, leaves dispersed along stems;

pseudoscapes 0–12 cm;

cataphylls 0–7 mm, prominently veined.

Leaves

palmately 3–6-foliolate;

stipules tardily deciduous proximally, persistent distally, linear, 8–18 × 2–4 mm, rarely glandular, glabrous;

petiole not swollen or jointed basally, slightly canaliculate, 2–55 mm, strigose;

petiolules 1–4 mm;

leaflet blades oblanceolate to narrowly elliptic or orbiculate, 1.1–4.5 × 0.6–2.2 cm, base attenuate, apex acute, acuminate to apiculate, surfaces abaxially sparsely to densely sericeous, rarely eglandular, adaxially glabrous or less sericeous.

palmately (3–)5–7-foliolate;

stipules persistent, triangular, 2–8(–9) × 1–5 mm, glandular and strigose abaxially;

petiole jointed to stem, 12–80 mm, strigose;

petiolules 1–3 mm;

leaflet blades oblanceolate, ovate, or rhombic, (0.6–)1.2–2.6 × (0.3–)1–2 cm, base cuneate, apex rounded to retuse, usually apiculate, surfaces glandular, abaxially uniformly strigose, adaxially strigose to glabrate or with hairs concentrated along veins.

Inflorescences

persistent, oblong, elongate;

rachis 0–6 cm, exposed, nodes (1 or)2–4(–8), (1–)3 flowers per node, internodes 3–7(–17) mm;

bracts persistent, linear to lanceolate or elliptic, 3–9 × 1.5–4 mm, sericeous.

persistent, umbellate or subcapitate, rarely reduced to a single flower;

rachis 0–0.8 cm, nodes 1–7, 3 flowers per node, internodes 1–2(–4) mm;

bracts tardily deciduous or persistent, lanceolate to narrowly elliptic, sometimes short-cupulate, 2–7 × 1–3 mm, glandular and strigose abaxially.

Peduncles

3–9 cm, longer than subtending petiole, densely white-strigose.

0.2–1.3 cm, shorter than subtending petiole, strigose.

Pedicels

0.5–1 mm.

1–2.5(–4) mm.

Flowers

7–11 mm;

calyx elongating and becoming broadly and shallowly campanulate in fruit but not gibbous, 6–8 mm abaxially, 4–6 mm adaxially, glandular (glands often hidden by hairs), sericeous (sometimes sparsely so);

tube 2–3 mm;

lobes linear-lanceolate to lanceolate, abaxial 4.5–5 × 2–2.5 mm, adaxial 1.5 × 1 mm;

corolla deep blue, banner oblanceolate to obovate or orbiculate, 6–7.5 × 3.5–5 mm with claw 1.5–2 mm, wings 6–7 × 1.5–2.5 mm with claw 2–2.5 mm, keel 5–6 × 1.5–2 mm with claw 2–3 mm;

filaments 4.5–5 mm;

anthers elliptic, 0.4 mm;

ovary glabrous proximally, canescent on distal 2/3, style canescent basally.

(7–)8–11(–12) mm;

calyx gibbous-campanulate in fruit, 5.5–10 mm abaxially, 4.5–8 mm adaxially, glandular, pubescent;

tube 3–4 mm;

abaxial lobe elliptic to oblanceolate, 2.5–7 × 1.5–2 mm, adaxial lobes triangular, 2–4(–5) × 1 mm;

corolla blue-purple, banner white or paler than other petals, oblanceolate, 9–11 × 4–5.5 mm with claw 2.5–3 mm, wings 9–11 × 2–3 mm with claw 3.5–4 mm, keel 7–8 × 2 mm with claw 3–4 mm;

filaments 6–6.5 mm;

anthers ovate, 0.3 mm;

ovary glabrous, style pubescent basally.

Legumes

narrowly oblong, 5–6 × 3–4.5 mm, obscurely glandular, tomentose, beak 3–5 mm, equal to or slightly longer than calyx.

globose to ovoid, 5–6 × 4 mm, glandular and short-strigose distally, beak broad, slightly arcuate, 5–6 mm, exserted beyond calyx.

Seed

red-brown, round-reniform, 4–5 × 3–4 mm, dull.

gray-green to red-brown, oblong-reniform, 4.5–5 × 3.5–4 mm, shiny.

2n

= 22.

Pediomelum argophyllum

Pediomelum aromaticum

Phenology Flowering summer. Flowering spring–summer.
Habitat Grasslands. Rocky clay or sandstone soils, barren or open places in pinyon-juniper wood­lands.
Elevation 200–1500 m. (700–4900 ft.) 1000–2000 m. (3300–6600 ft.)
Distribution
from FNA
CO; IA; IL; KS; MN; MO; MT; ND; NE; NY; OK; SD; TX; WI; WY; AB; MB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; UT
[BONAP county map]
Discussion

Pediomelum argophyllum is unique in the genus in its gray, silvery pubescence, earning it the common name silverleaf Indian breadroot. It has one of the widest distributions of its congeners, ranging from Canada to Texas, but seems more prevalent in the northern states. It has been used by native cultures for food or medicine for at least 2500 years (D. F. Dexter et al. 2014).

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

Pediomelum aromaticum is known from Mohave County in Arizona, Montrose County in Colorado, and southern Utah.

In the past, varieties were recognized based on the number of flowers per node, flower and peduncle length, and stem robustness. These varieties are largely confined to distinct geographical populations or areas. Variety ambiguum was described from Little Valley in Grand County as having long peduncles (5–28 mm) and an often bidentate abaxial calyx tooth. Variety barnebyi was described from populations from the Canaan Mountain region in Washington county and adjacent Arizona, an area at the westernmost edge of the P. aromaticum distribution. These plants are more robust than others, have more flowers per inflorescence, and have longer peduncles, but plants from across the range show similar robustness with number of flowers per inflorescence varying widely. Variety tuhyi was described as differing from var. aromaticum in having flowers smaller than 9 mm, coupled with decumbent stems. J. W. Grimes (1990) pointed out that mature flowers on several collections, including the holotype, are longer than 9 mm, and not all plants are decumbent.

(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. aromaticum, P. californicum, P. canescens, P. castoreum, P. cuspidatum, P. cyphocalyx, P. digitatum, P. epipsilum, P. esculentum, 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. californicum, P. canescens, P. castoreum, P. cuspidatum, P. cyphocalyx, P. digitatum, P. epipsilum, P. esculentum, 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
Synonyms Psoralea argophylla Psoralea aromatica, P. aromaticum var. ambiguum, P. aromaticum var. barnebyi, P. aromaticum var. tuhyi
Name authority (Pursh) J. W. Grimes: Mem. New York Bot. Gard. 61: 69. (1990) (Payson) W. A. Weber: Phytologia 53: 188. (1983)
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