Pediomelum esculentum (Pursh) Rydb.
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Authority
Grimes, J. E. 1990. A revision of the New World species of Psoraleeae (Leguminosae: Papilionoideae). Mem. New York Bot. Gard. 61: 1-114.
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Family
Fabaceae
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Scientific Name
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Description
Species Description - Eglandular perennial herbs to 0.5 m tall, usually erect and unbranched, occasionally sparingly branched near the base, more rarely these branches branched again, or sometimes plants acaulescent, lower peduncles and petioles arising more or less perpendicular to the stem, plants at least partly hirsute with hairs to 3.0 mm and with some shorter appressed pubescence; swollen portions ofthe roots usually subapical, pseudoscapes usually only 0.5-2 cm; stems densely villose-hirsute and appressed-pubescent at base, sparingly so above, or with only appressed hairs, lowest nodes of stem, and those of the pseudoscapes with striate cataphylls to 15 mm . Stipules 12-20 X 2-8 mm , sparingly pubescent with semi-erect hairs to 2.5 mm , usually stramineous at base, green above, the lower ones broadly lanceolate, sometimes asymmetrically so, sometimes obviously veined, the upper stipules becoming linear-elliptic or linear-lanceolate, persistent. Leaves palmately 3-5-foliolate, the 3-foliolate ones appearing appearing later in the year; petiole 0.2-15 cm, round to more usually slightly canaliculate, striate, the base scarcely of different color or texture and not obviously jointed to stem; petiolules 1.5-4 mm , blond to dark brown and pubescent with long semierect hairs; leaflets broadly elliptic, ellipticoblanceolate or oblanceolate, 2.0-6.0 x 0.7-2.3 cm, obtuse, broadly acute to retuse at apex, often apiculate, attenuate to cuneate at base, upper surface glabrous except on midvein, rarely pubescent near petiolule, lower surface uniformly sparingly to densely pubescent with long semierect hairs. Inflorescence in outline elliptic to oblong, with (6-)8-15 nodes and (2-)3 flowers per node; peduncle 0.5-11.5 cm; rachis 1.6-7.0 cm, elongating slightly in fruit, internodes 0.0-7.0 mm; bracts persistent, elliptic, round or oblanceolate, 5-15 X 0.5-8 mm, acuminate to cuspidate at apex, glabrate to very sparingly pubescent; pedicels 1.5-3 mm . Flowers 12-20 mm; calyx uniformly pubescent with hairs to 2.5 mm , 12-14 mm long to upper teeth, 13-16 mm long to lower tooth, the tube usually blond, 5-5.5 mm, the teeth green, the upper four linear-lanceolate, 4-7 X 1-1.5 mm , lower one elliptic to lanceolate, 7.5-9.5 X 2-2.5 mm , teeth internally pubescent at base, glabrate at apex, the calyx in fruit strongly gibbose-campanulate, with veins to the apex of each tooth and one to each sinus, those of sinuses bifurcating and produced as very faint submarginal nerves on the teeth; petals violet to blue-purple; banner oblanceolate, 17-18 x 6 mm, the claw 7-8 mm, the blade emarginate, biauriculate, the auricles scarcely internally callose; wings 15-16.5 X 3-3.5 mm, the claw 6.5 mm, the auricle 1.5-2 mm; keel petals 12-12.5 x 3 mm, the claw 6-6.5 mm; androecium 11-14 mm, anthers elliptic, 0.5 mm; gynoecium 10-13 mm, ovary pubescent at apex, the styles pubescent to beyond middle. Fruit body oblong in profile, 4-6 X 2.5-3.5 mm, eglandular, glabrous except at style base, commonly with evident dorsal and ventral grooves, abruptly narrowed to an arcuate, pubescent beak 10-16 mm, this surpassing calyx teeth. Seed reniform in profile, 4 x 3 mm, somewhat rugose, brown.
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Discussion
Holotypus PH! non Psoralea esculenta Nutt. in Eraser's Catalogue, 1813, as reprinted by Greene, Pittonia 2: 118. 1890, nomen nudum. Lotodes esculentum (Pursh) Kuntze, Revis. gen. pi. 1: 194. 1891.
Psoralea brachiata Douglas ex Hook., R. bor.-amer. 1:137.1831. "Plains ofthe Saskatchewan from Carlton House to Edmonton House, Drummond." Holotypus BM! isotypi F! GH! K!
n historically complex species that, since the separation of P. hypogaeum var. subulatum, is easily recognized on the basis of its strictly eglandular nature, mostly caulescent habit and stipules strictly free. Torrey and Gray in Rora of North America were the first to indirectly propose this strict definition of P. esculentum when they proposed '^Psoralea esculenta |S, nearly stemless, leaflets obovate-oblong" (authentic specimen NY!). This taxon was legitimately published as Psoralea subulata Bush in 1919, and is herein transferred to Pediomelum hypogaeum var. subulatum. Unfortunately, this has transferred some taxonomic problems from P. esculentum to P. hypogaeum. Until now, Pediomelum esculentum and P. hypogaeum have been considered to be very closely related. In fact, Ockendon (1965) claimed that they would have to be placed close together in any natural system. Though depauperate specimens of P. esculentum may sometimes bear striking resemblance to P. hypogaeum var. subulatum I cannot agree that they are closely related. Pediomelum hypogaeum var. subulatum has the deciduous inflorescence characteristic of subgenus Disarticulatum, while that of P. esculentum is persistent.
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Distribution
A species of prairies, open pine forest and grasslands at ca. 500-2000 m , in the Great Plains of North America from Alberta, Saskatchewan, and Manitoba, south to Oklahoma, northeastern New Mexico (Union Co.), northwestern Arkansas; from the foothills ofthe Rockies (Montana, Wyoming and Colorado (Yuma Co.)) east to westem Wisconsin, Iowa and Missouri. Fl.
Canada North America| United States of America North America| Alberta Canada North America| Saskatchewan Canada North America| New Mexico United States of America North America| Arkansas United States of America North America| Montana United States of America North America| Wyoming United States of America North America| Colorado United States of America North America| Wisconsin United States of America North America| Iowa United States of America North America| Missouri United States of America North America|