Friday, March 31, 2023

[Botany • 2023] Coutaportla helgae (Rubiaceae: Chiococceae) • A New Species from Sinaloa, México


Coutaportla helgae Pío-León, Torr.-Montúfar et H. Ávila,

in Pío-León, Torres-Montúfar et Ávila-González, 2023. 

Background and Aims: During explorations in the outer limits of the Natural Protected Area Sierra de Tacuichamona, an endemic-rich area of Sinaloa, Mexico, a new species of Coutaportla (Rubiaceae) was discovered. This paper describes and illustrates Coutaportla helgae, provides an identification key, a distribution map, and discusses the morphological and geographic relationships with the rest of the species of the genus.

Methods: Botanical collections were made during 2021 and 2022, and 15 herbariums and digital databases were reviewed to compare with other species of the genus and to locate possible additional localities. A distribution map was prepared using the polygon of the Sierra Madre Occidental as a base.

Key results: Coutaportla helgae stands out from the rest of the species of the genus by having the smallest flowers of the group. It is morphologically related to C. lorenceana as they are the only species of the genus with subapical placentation and calyx lobes less than half the length of the fruit, but it differs in having smaller flowers, a shrubby habit and distribution in tropical deciduous forest.

Conclusions: With the present discovery, Coutaportla reaches four endemic species to Mexico and five overall, considering C. guatemalensis. Coutaportla helgae contributes new characteristics to the genus by having smaller flowers and growing at lower altitudes than the rest. Additionally, elements are provided to support the conservation of sites with high biodiversity and endemism such as the Sierra Tacuichamona.

Keywords:  Cosalá, endemism, flora, Tacuichamona montains, tropical deciduous forest

Illustration: Ericka Belén Cortez

Coutaportla helgae Pío-León, Torr.-Montúfar et H. Ávila, sp. nov. 

Coutaportla helgae differs from all the other species in the genus by the shrub lifeform, small corolla (up to 1.3 cm long), the subapical ovule placentation and the capsules with one-seeded locules. It most closely resembles C. lorenceana by the subapical ovule placentation, but differs in the shrub lifeform (vs. treelet in C. lorenceana) and the white corolla with purple folds (vs. completely purple corol-las in C. lorenceana).

Juan F. Pío-León, Alejandro Torres-Montúfar and Heriberto Ávila-González. 2023. Coutaportla helgae (Rubiaceae), A New Species from Sinaloa, México. Acta Botanica Mexicana. 130; DOI: 10.21829/abm130.2023.2167