Desmanthus leptolobus | ‘Prairie Mimosa’, ‘Prairie Bundleflower’, ‘Slenderlobe Bundleflower’ | 20 seeds
Desmanthus leptolobus is another of our EU exclusives – trust us when we say this is not a species for which it is easy to obtain seed (in any amount) – especially given that it’s reportedly only seriously collected by one individual in America! Happily, we’ve managed to secure an extremely limited supply of this much sought-after species from a European grower (currently, we seem to be the only source worldwide for this species? Let us know if you know of any other supplier which has it in stock), so order now if you want to grow this elusive plant…
A flowering perennial shrub native to parts of the USA, Desmanthus leptolobus is commonly known as the ‘Prairie Mimosa’, ‘Prairie Bundleflower’ or ‘Slenderlobe Bundleflower’. It’s closely related to the far more common Desmanthus illinoensis, with which it often co-occurs in the wild. The two species can be told apart most easily by the shape and size of their respective seed pods – leptolobus produces fewer, longer and narrower pods than illinoensis, which forms dense clusters of short flattish pods. Leptolobus is also generally shorter and more prostrate than its sibling species. While the two species may often be found growing together, they do not form hybrids to any noticeable degree. The species is one of several early-appearing components of land-reclamation vegetation, which rapidly disappears once shrub and tree species establish themselves.
Growing easily from seed in USDA Hardiness Zones 5-8 (it can handle freezes down to ~-20°C), Desmanthus leptolobus grows fairly erect when young from its woody base, often later turning to a more prostrate form. Its few to numerous reddish-green trailing stems grow up to roughly a metre in length, while its tapering cylindrical taproot has been observed to reach up to a metre and a half, although only attains one to two centimetres in diameter. The leaves of leptolobus grow from around two and a half centimetres to six or so centimetres long, while its curved, almost stalk-less, pointy leaflets are approximately two to five centimetres long by five to ten millimetres wide. The latter are narrowly elliptic to linear and are arranged in fifteen to twenty-five pairs.
A highly rewarding plant to grow from seed, germination is improved by slight scarification and/or a twelve to twenty-four hour soak pre-treatment. A proper guide will follow soon, but for now you might like to take a look at the Desmanthus illinoensis grow guide in our Cultivation section – they’re fairly similar in requirements.
All the seed sold by Arkham’s Botanical was freshly and ethically sourced in 2018