Biserrula pelecinus L. is a Mediterranean annual pasture legume and performs best on well drained sandy loams and medium loams with a pH 4.5–7. It is not suited to areas prone to waterlogging but persists well, even with hard summer grazing and in rotational systems. It is deep-rooted and remains green long after traditional pastures have dried off. Diversity analysis of germplasm collection of 279 accessions using 18 agro-morphological traits, 22 eco-geographical specifications of the collection sites, and amplified fragment length polymorphisms markers was conducted to develop a core collection of ∼10% of the original collection. This core collection of 30 accessions from seven countries well represented the diversity of the whole collection. This core will be exploited for variation in photosensitivity effect in sheep together with other economically important traits challenging the livestock industry.