Lotus (genus)

Lotus is a genus that includes bird's-foot trefoils and deervetches and contains many dozens of species distributed world-wide. Depending on the taxonomic authority, roughly between 70 and 150 are accepted. Lotus is a genus of legume and its members are adapted to a wide range of habitats, from coastal environments to high altitudes. Most species have leaves with five leaflets; two of these are at the extreme base of the leaf, with the other three at the tip of a naked midrib. This gives the appearance of a pair of large stipules below a "petiole" bearing a trefoil of three leaflets – in fact the true stipules are minute, soon falling or withering.^[1] Some species have pinnate leaves with up to 15 leaflets. The flowers are in clusters of 3-10 together at the apex of a stem with some basal leafy bracts; they are pea-flower shaped, usually vivid yellow, but occasionally orange or red. The seeds develop in three or four straight, strongly diverging pods, which together make a shape reminiscent of the diverging toes of a small bird, leading to the common name "bird's-foot".

The genus Lotus is currently undergoing extensive taxonomic revision. All species native to California (30 spp.) have been recently moved to the genera Acmispon and Hosakia in the Second Edition of The Jepson Manual.

Uses and ecology

Lotus species are used as food plants by the larvae of some Lepidoptera species. See list of Lepidoptera that feed on Lotus. Several species are culvivated for forage, including L. corniculatus, L. glaber and L. pedunculatus. They can produce toxic cyanogenic glycosides which can be potentially toxic to livestock, but also produce tannins, which are a beneficial anti-bloating compound.

This genus can fix nitrogen from the air courtesy of their root nodules, making it useful as a cover crop. The nodulating symbionts are Bradyrhizobium bacteria. Scientific research for crop improvement and understanding the general biology of the genus is focused on Lotus japonicus which is currently the subject of a full genome sequencing project, and is considered a model organism.

Some species, such as L. berthelotii from the Canary Islands, are grown as ornamental plants. L. corniculatus is an invasive species in some regions of North America and Australia.

Selected species

• Lotus aboriginus – Rosy Bird's-foot Trefoil
• Lotus aduncus
• Lotus alamosanus – Sonora Bird's-foot Trefoil
• Lotus alpinus
• Lotus angustissimus – Slender Bird's-foot Trefoil
• Lotus argophyllus – Silver Bird's-foot Trefoil
• Lotus argyraeus – Canyon Bird's-foot Trefoil
• Lotus australis – Austral Trefoil
• Lotus benthamii – Bentham's Deervetch

• Lotus berthelotii – Canary Islands Trefoil
• Lotus cedrosensis
• Lotus corniculatus – Common Bird's-foot Trefoil, Bird's-foot Deervetch
• Lotus crassifolius – Big Deervetch, Broad-leaved Bird's-foot Trefoil
• Lotus creticus
• Lotus dendroideus – Island Deervetch
• Lotus denticulatus – Riverbar Bird's-foot Trefoil, Meadow Bird's-foot Trefoil
• Lotus formosissimus – Seaside Bird's-foot Trefoil
• Lotus glaber – Narrow-leaved Bird's-foot Trefoil, Slender Trefoil, Creeping Trefoil, Prostrate Trefoil; formerly L. tenuis
• Lotus grandiflorus – Chaparral Bird's-foot Trefoil
• Lotus greenei – Greene's Bird's-foot Trefoil
• Lotus hamatus – San Diego Bird's-foot Trefoil
• Lotus haydonii – Rock Bird's-foot Trefoil
• Lotus heermannii – Heermann's Bird's-foot Trefoil
• Lotus humistratus – Foothill Deervetch
• Lotus incanus – Woolly Bird's-foot Trefoil
• Lotus intricatus – Arid Bird's-foot Trefoil
• Lotus jacobaeus
• Lotus japonicus
• Lotus junceus – Rush Deervetch
• Lotus maculatus
• Lotus maritimus
• Lotus mearnsii – Mearns' Bird's-foot Trefoil
• Lotus micranthus – Desert Deervetch
• Lotus mollis
• Lotus nevadensis – Nevada Bird's-foot Trefoil
• Lotus nuttallianus – Wire Bird's-foot Trefoil
• Lotus oblongifolius – Streambank Bird's-foot Trefoil
• Lotus ononopsis
• Lotus ornithopoides
• Lotus palustris
• Lotus parviflorus – Smallflower Bird's-foot Trefoil, Smallflower Trefoil
• Lotus pinnatus – Meadow Bird's-foot Trefoil, Bog Bird's-foot Trefoil
• Lotus plebeius – New Mexico Bird's-foot Trefoil
• Lotus procumbens – Silky Deerweed
• Lotus purshianus – Spanish Clover
• Lotus rigidus – Desert Rock Pea, Shrubby Deervetch
• Lotus rubriflorus – Redflower Bird's-foot Trefoil
• Lotus salsuginosus – Coastal Bird's-foot Trefoil
• Lotus scoparius – Common Deerweed, Common Deervetch, California Broom, Western Bird's-foot Trefoil
• Lotus sessilifolius
• Lotus stipularis – Balsam Bird's-foot Trefoil
• Lotus strigosus – Strigose Bird's-foot Trefoil
• Lotus subbiflorus – Hairy Bird's-foot Trefoil
• Lotus tetragonolobus – Winged Bird's-foot Trefoil
• Lotus unifoliolatus – American Bird's-foot Trefoil
• Lotus pedunculatus – Greater Bird's-foot Trefoil, Marsh Bird's-foot Trefoil, Large Bird's-foot Trefoil, Big Trefoil; formerly L. uliginosus.
• Lotus utahensis – Utah Bird's-foot Trefoil
• Lotus wrangelianus – Chilean Bird's-foot Trefoil
• Lotus wrightii – Wright's Deervetch
• Lotus yollabolliensis – Yolla Bolly Bird's-foot Trefoil

References

External links

• Lotus species names