Saturday, May 11, 2024

[Botany • 2024] Castrila latens (Rubiaceae: Rubieae) • A New plant Genus and Species from south-eastern Spain

 

Castrila latens Blanca, S.Ben-Menni, H.Blanca, Cueto, J.Fuentes, Ortega Oliv. & Suár.-Sant., 

in G. Blanca, Schuler, H. Blanca, Cueto, Fuentes, Ortega-Olivencia et Suárez-Santiago, 2024. 
 
Abstract
A new genus and species, Castrila latens, native to the south-eastern Iberian Peninsula, is described here for the first time and compared with its closest relatives. The plant is characterized by being annual, glabrous, having reduplicate leaves in whorls of (5)6–7, inflorescences capitate and involucrate, corolla shortly hypocrateriform and white, with yellowish doliiform tube, stamens included, and ovary and mericarps densely papillose. An endemic plant, it grows on the calcareous mountains of the Sierra Seca, Sierra de Castril, and Sierra de la Cabrilla, between 1800 and 2100 m of elevation, in the Granada and Jaén provinces (eastern Andalusia, Spain). For this genus and species, a description, an illustration, a distribution map, the chromosome number, the assessment of the conservation status, an estimate of the breeding system, and the situation in the Rubieae phylogenetic tree are provided.

Keywords: endemic plants, Iberian Peninsula, monospecific genus, paraphyly, phylogeny, taxonomy


Castrila Blanca, S.Ben-Menni, H.Blanca, Cueto, J.Fuentes, Ortega Oliv. & Suár.-Sant., gen. nov. 
– Type: Castrila latens Blanca et al.

Description: Herbaceous annual, glabrous. Stems erect, simple or divaricate, delicate. Stem leaves in whorls of (5)6 or 7, sessile, uninervous, reduplicate. Inflorescences capitate, 1–3 on the top of the stems, involucrate, composed of shortly pedunculated and bracteolate cymes. Flowers hermaphrodite, tetramerous; calyx absent; corolla shortly hypocrateriform, with tube doliiform, and lobes patent, triangular, obtuse, not apiculate, white. Stamens included, inserted near the base of the tube, with anthers linear, dorsifixed, yellow. Gynoecium with ovary papillose, topped in two globose stigmas. Mericarps ellipsoidal, densely papillose, blackish.


Castrila latens Blanca, S.Ben-Menni, H.Blanca, Cueto, J.Fuentes, Ortega Oliv. & Suár.-Sant., sp. nov.

Castrila latens. A, Habit; B, Leaves detail; C, Inflorescences detail; D, Ovary, style and stigmas; E, Fruits; F, Mitotic metaphase with 2n = 22 chromosomes (Castril, Sierra Seca, GDA 70863).
— Photos: A, D & E, Gabriel Blanca; B & C, Julián Fuentes; F, Víctor N. Suárez-Santiago.

Castrila latens (GDA 70863, holotype).
A, General appearance; B, Basal leaf; C, Stem leaf; D, Inflorescence detail; E, Flower front view; F, Flower lateral view; G, Flower longitudinal section; H, Fruits.
— Draw by Manuel García.

Etymology: The genus name refers to the municipality of Castril (Granada Province, eastern Andalusia, south-eastern Spain) where the species was first found. The specific epithet “latens” comes from Latin, meaning “hiding” or “escaping notice”, because of the difficulty of detecting this plant in the field, mainly due to its small size, its mimicry with depauperate specimens of other tetramerous species and its brief flowering period.



Gabriel Blanca, Samira Ben-Menni Schuler, Helena Blanca, Miguel Cueto, Julián Fuentes, Ana Ortega-Olivencia and Víctor N. Suárez-Santiago. 2024. A New plant Genus and Species from south-eastern Spain: Castrila latens (Rubieae, Rubiaceae). TAXON. DOI: 10.1002/tax.13181