Department of Biological Sciences, Bolus Herbarium, University of Cape Town, Cape Town, South Africa.
Department of Botany, Systematics Laboratory, Gombe State University, Gombe, Gombe State, Nigeria.
PLoS One. 2023 Mar 16;18(3):e0280550. doi: 10.1371/journal.pone.0280550. eCollection 2023.
Tinnea gombea, endemic to the Sudan savanna grasslands in northern Nigeria, is described and illustrated. We used integrative evidence from morphological characters, ecology and molecular phylogenetic data. The new species is morphologically and ecologically similar to T. barteri and T. aethiopica, but can be readily delimited from these taxa by unique characters including a subshrub growth habit, leaves alternate to subopposite, blades lanceolate, apically acuminate, inflorescences raceme, bearing solitary flowers in upper leaf and bract axils, lilac to purplish dusky flowers and the inflated fruits dehiscent. The distribution and habitat of T. gombea are also distinctive, being restricted to the Sudan savanna, while the two most similar species are widespread in tropical Africa. Additionally, molecular phylogenetic assessments using nrITS and chloroplast trnL-F, matK and rbcL support the placement of T. gombea as a distinct species. Tinnea gombea is here assessed as Critically Endangered due to its small population size and restriction to a small area lacking conservation prioritization.
冈比亚铁线蕨，分布于尼日利亚北部苏丹草原，本文对其进行了描述和图示。我们综合了形态特征、生态学和分子系统发育数据等方面的证据。新种在形态和生态上与 T. barteri 和 T. aethiopica 相似，但通过独特的特征可以很容易地将其与这些类群区分开来，包括亚灌木生长习性、互生或近对生叶、叶片披针形、先端渐尖、总状花序、在上部叶和苞片腋部着生单花、淡紫色到紫黑色暗紫色花和膨胀的果实开裂。冈比亚铁线蕨的分布和生境也很独特，仅限于苏丹草原，而最相似的两个物种则广泛分布于热带非洲。此外，使用 nrITS 和叶绿体 trnL-F、matK 和 rbcL 进行的分子系统发育评估支持将 T. gombea 作为一个独特的物种进行分类。由于种群规模小，且局限于缺乏保护优先级的小区域，冈比亚铁线蕨被评估为极危物种。
