Species delimitation remains a crucial issue for widespread plants occurring across forest-savanna ecotone such as Lophira (Ochnaceae). Most taxonomists recognize two parapatric African tree species, widely distributed and morphologically similar but occurring in contrasted habitats: L. lanceolata in the Sudanian dry forests and savannahs and L. alata in the dense Guineo-Congolian forests. Both species co-occur along a ca. 3000 km long forest-savanna mosaic belt, constituting ideal models for investigating hybridization patterns and the impact of past glacial periods on the genetic structures in two types of ecosystems. We genotyped 10 nuclear microsatellites for 803 individuals sampled across the distribution range of Lophira. Both species exhibit similar levels of genetic diversity [He = 0.52 (L. alata); 0.44 (L. lanceolata)] and are well differentiated, consistent with taxonomic delimitation (F_ST = 0.36; R_ST = 0.49), refuting the hypothesis that they might constitute ecotypes rather than distinct species. Furthermore, L. alata displayed two deeply differentiated clusters (F_ST = 0.37; R_ST = 0.53) distributed in parapatry, one endemic to Western Gabon while another cluster extended over the remaining species range, suggests that L. alata is made of two cryptic species. We showed that rare hybrids occur in some contact zones between these three species, leaving a weak signal of introgression between L. lanceolata and the northern cluster of L. alata. At the intra-specific level, the latter species also show weak genetic structuring between Upper and Lower Guinea and the intensity did not differ strikingly between rainforest and savanna ecosystems. The discovery of a new species of Lophira with a narrow distribution in West Gabon where it is intensively exploited for its timber requires to evaluate its conservation status.

物种划界仍然是整个森林-热带稀树草原过渡带上广泛存在的植物的关键问题，例如Lophira（Ochnaceae）。大多数分类学家识别两个parapatric非洲树种，分布广泛，形态类似，但在对比栖息地发生：L.杉木在Sudanian干燥森林和热带稀树草原和L.翅在密集Guineo-Congolian森林。两种物种都沿着一个ca同时发生。3000公里长的森林-热带稀树草原马赛克带，是研究杂交模式以及过去冰川期对两种生态系统遗传结构的影响的理想模型。我们对Lophira分布范围内的803个人进行了10个核微卫星基因分型。两种物种的遗传多样性水平相似[ H e = 0.52（L. alata）; （L. lanceolata）0.44（L. lanceolata）]并进行了很好的区分，与分类学划界一致（F _ST = 0.36; R _ST = 0.49），驳斥了它们可能构成生态型而不是不同物种的假设。此外，L.翅显示的两个深深分化簇（˚F _ST = 0.37; [R _ST = 0.53）分布在parapatry，一个特有的西方加蓬而延长在剩余物种范围中的另一集群，表明L.翅由两个神秘物种组成。我们发现，发生在这三个品种之间的一些接触区域罕见的杂种，留之间渗入的微弱信号L.杉木和北部集群L.翅。在种内水平上，后一种物种在上几内亚和下几内亚之间的遗传结构也较弱，其强度在雨林和热带稀树草原生态系统之间没有显着差异。在西加蓬发现了分布较窄的洛菲拉新物种，在那里对其木材进行了大量开发，因此需要评估其保护状况。