A widespread lineage of bulbous monocots.

What are the Ledebouriinae?

The Ledebouriinae (Scilloideae; Asparagaceae) are a group of bulbous monocots found across sub-Saharan Africa, with a handful of taxa in Madagascar, Yemen, India, and Sri Lanka. Phylogenetic relationships within the group have been historically difficult to recover. Using field- and museum-based collections combined with the Angiosperms353 sequence capture probe set, we provided the first phylogenomic perspective of the group. We found that historical taxonomic concepts were valid except for Ledebouria, which should likely be split into two entities. We also found evidence for historical hybridization between Ledebouria and Drimiopsis, which may be cause for high discordance within one of the Ledebouria lineages.

Ledebouriinae diversity is still largely undescribed due to significant morphological plasticity and low taxon sampling across their distribution. The group not only holds great potential for better understanding plant evolution in Africa, but also ploidal, morphological, and ecological evolution overall. For example, in Namibia alone, Ledebouria species display wide variation in leaf, bulb, and flower morphology, with a few hysteranthous species. Their ease of cultivation (e.g., in a greenhouse) allows for ex situ experimental (e.g., common garden experiments) and developmental studies in addition to phylogenetic refinement. Improving our understanding of species relationships, population dynamics, biogeography, and morphology are long-term goals for the Ledebouriinae by expanding upon existing international partnerships in Africa. Other outstanding, unexplored topics include but are not limited to pollinator interactions, flower morphology, physiology and its ecological/morphological relationship, and ploidal evolution.

Relevant Publications

Howard CC, L Nanyeni, N Mollel, D Chuba, AR Zuntini, P Malakasi, TS Harvey, N Cellinese. From southern Africa and beyond: Historical biogeography of a monocotyledonous bulbous geophyte. Journal of Biogeography. 2023. https://doi.org/10.1111/jbi.14627

Howard CC, AA Crowl, TS Harvey, N Cellinese. Peeling back the layers: complex dynamics shaping the evolution of the Ledebouriinae (Scilloideae, Asparagaceae). Molecular Phylogenetics & Evolution. 2022. doi.org/10.1016/j.ympev.2022.107430

Howard CC. In the Shade of the Mopane: Ledebouria in Namibia. Cactus & Succulent Journal 86 (4): 2014. doi.org/10.2985/015.086.0301

Howard CC. Ledebouria scabrida: a Namibian endemic? The Bulb Garden 13(1): 2014.