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| Dalea rubriflora A.E. Estrada, J. Martínez-Ramírez, A. Mares & Ocampo in Castillón, Ramírez, Mares-Guerrero & Ocampo, 2020. |
Abstract
We describe and illustrate Dalea rubriflora A.E. Estrada, J. Martínez-Ramírez, A. Mares & Ocampo as a new species from central Mexico. According to the morphology of its flower, this new species is included in a new section within subgenus Parosela because the shape of its keel, the innermost petals (which make the flower valvate) coherent along their external (dorsal) outer margins. However, this new species and new section have striking differences with the rest of the previously described taxa of subgenus Parosela, highlighting 1) the persistent red color of the flowers, not found in any section and species of Dalea, 2) the stamens are joined in a very long staminal column which are protruded from the keel petals for almost a third of its length, and 3) the blades of the epistemonous petals are not auriculated, instead, are truncated in the keel and absent in the wings. These main features, associated with more particular characteristics of other sections, allow us to recognize Rubriflorae as a new section and Dalea rubriflora as a new species into the subgenus Parosela.
Keywords: Eudicots, Central Mexico, Leguminosae, sect. Rubriflorae, Sierra del Laurel, Zacatecas
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| Figure 2. Dalea rubriflora, A) Habit. B) Inflorescence showing its bracts, red flowers, and protruded stamens. |
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| Figure 1. Dalea rubriflora, A) Flowering habit. B) Leaf stipules. C) Bracts, left side, adaxial view, with the apex curved inward; right side, abaxial view, with the apex straight D) Whole calyx showing glandiform spurs, one on each side at the base of each tooth. E) Whole flower showing the stamens protruding 3–5 mm from keel. F) Banner front view (left) and profile (right). G) Wing. H) Keel. I) Stamens. J) Gynoecium. |
Dalea sect. Rubriflorae A.E. Estrada, sect. nov.
Type:— Dalea rubriflora A.E. Estrada, J. Martínez-Ramírez, A. Mares & Ocampo.
Etymology:— The name Rubriflorae of this monotypic section is derived from the red color (permanent ruby
red color, even when dried) of its flowers. We added a key to recognize and to differentiate sect. Rubriflorae from the
sections recognized by Barneby (1964).
Dalea rubriflora A.E. Estrada, J. Martínez-Ramírez, A. Mares & Ocampo, sp. nov.
Morphologically similar to Dalea viridiflora S. Watson (1886: 448) in growth form and single terminal spiked
inflorescences; however, D. rubriflora has higher number of leaflets (11–16 vs. 7–11 pairs), much longer peduncles
(11.5 cm long vs. 0.5–4 cm long), caducous bracts (persistent in D. viridiflora), and longer flower structures (calyx,
banner, wings, keel, staminal tube, filaments, and anthers).
Distribution and habitat:— As far as known, there is only one collection of Dalea rubriflora. The species was
found in an oak forest with elevation of 2590 m in an area locally known as “Sierra del Laurel” (Fig. 3). More collection
efforts are needed to know the actual distribution of the species, although it is likely to occur in the neighboring areas
of the states of Aguascalientes and Jalisco.
Etymology:— The epithet of the species refers to the characteristic and permanent red color of its flowers (Fig.
2). To our knowledge, this is the only species in the genus Dalea whose petals are completely red and keep this color
even when the petals are dry. The banner has a yellow spot on its central part, but when the material is dried changes
to white, although the rest of the banner remains red on both, inner and outer surfaces.
Eduardo Estrada Castillón, Julio Martínez Ramírez, Andrés Alejandro Mares-Guerrero and Gilberto Ocampo. 2020. A New Outstanding Species and A New Section of Dalea (Fabaceae: Papilionoideae) from central Mexico. Phytotaxa. 454(2); 145–152. DOI: 10.11646/phytotaxa.454.2.6
