Orbexilum Explained

Orbexilum, commonly called leather-root, is a genus of flowering plants in the legume family (Fabaceae). They are native to North America, where they are found in the United States and Mexico, south to Chiapas.^[1]

This genus can be distinguished from other genera in the Psoraleeae by its "thick glabrous pod walls that are distinctively rugose and by [a] calyx that is scarcely accrescent."^[2]

Taxonomy

The genus was described by Constantine Samuel Rafinesque in 1832, with the type species O. latifolia, moved from Psoralea. (O. latifolia is now considered a synonym of O. onobrychis.^[3]) Rafinesque differentiated Orbexilum from Psoralea largely on the basis of features of the calyx.

Species

Orbexilum comprises the following species:^{[4] [2]}

• Orbexilum chiapasanum B.L.Turner
• Orbexilum lupinellus (Michx.) Isely
• †Orbexilum macrophyllum (Rowlee) Rydb. – bigleaf scurfpea^[5]
• Orbexilum melanocarpum (Benth.) Rydb.
• Orbexilum oliganthum (Brandegee) B.L.Turner
• Orbexilum onobrychis (Nutt.) Rydb.
• Orbexilum pedunculatum (Mill.) Rydb.
• Orbexilum psoralioides (Walter) Vincent, syn. Orbexilum gracile (Torr. & A.Gray) B.L.Turner
• Orbexilum simplex (Nutt. ex Torr. & A.Gray) Rydb.
• †Orbexilum stipulatum (Torr. & A.Gray) Rydb.
• Orbexilum virgatum (Nutt.) Rydb.

External links

• USDA Plants Profile

Notes and References

1. Web site: Flora of the Southern and Mid-Atlantic States . Alan Weakley . 2015.
2. Turner BL. . 2008 . Revision of the genus Orbexilum (Fabaceae: Psoraleeae) . Lundellia . 11 . 1–7 . 10.25224/1097-993X-1.11.1 .
3. Web site: Orbexilum latifolia . Plants of the World Online . Royal Botanic Gardens, Kew. 11 September 2023.
4. Web site: Orbexilum Raf. . Plants of the World Online . Royal Botanic Gardens, Kew. 2021-06-14 .
5. Web site: LeGrand. H. Sorrie. B. 2021. Account for Bigleaf Scurfpea. May 26, 2021. Vascular Plants of North Carolina. North Carolina Biodiversity Project and North Carolina State Parks.