Encelia balandra Leon De La Luz & Lichter-Marck, 2022

Leon-De La Luz, Jose Luis & Lichter-Marck, Isaac H., 2022, A new species of Encelia (Compositae, Heliantheae, Enceliinae) from the southern Baja California Peninsula, PhytoKeys 212, pp. 97-109 : 97

Encelia balandra Leon De La Luz & Lichter-Marck sp. nov.

Figs 2 , 3

Remark.

Capitulum anatomy, particularly solitary heads erect in fruiting, places this new species with members of the frutescens clade, such as E. frutescens and E. virginensis . Molecular analysis also places the species in alliance with the Frutescens clade. The combination of glabrous, epappose cypselae, strigose hairs, a suffruticose habit and solitary heads are unique to this species.

Description.

Deciduous perennial herb, suffrutescent, up to 40 cm high, with dense foliage when present. Leaves entire, fleshy, alternate, (2-)3 cm long × 1.5(-2) cm wide, ovate-lanceolate in outline, margins crenate, often with 4 conspicuous, symmetric lobes, basal pair larger than distal, petiole short 2-3 mm long, venation supra-basal and imperfect with 1 or 2 pairs of veins, apex acute, indumentum strigulose, eglandular, multicellular trichomes 1 mm, adpressed, with a semi-bulbose base. Solitary Inflorescence, capitula terminal, peduncles naked, 14-20 cm long in bloom, up to 25 cm in fruit. Capitula 2.5-3 cm diameter, heterogamous, radiate; involucre 1.5-2 cm diameter, phyllaries tri-seriate, 6-9 bracts per series, bracts herbaceous lanceolate to ovate-lanceolate, inner slightly larger than outer, inner 7-8 mm long × 2 mm wide, outer 6-7 mm long × 2 mm wide, occasionally villous at the apex, barely connate at base, scarious to touch, persistent after fruiting; receptacle chaffy, slightly convex, 13-15 mm diameter, 4-6 mm high, some paleaes empty <1 mm long, silky villous; paleaes subtending disc florets, scarious, concave, subulate, acrescent in age, up to 5 mm long × 3 mm wide, barely villous at ends. Ray florets neuter, 12-15, uniseriate, ray limb yellow, ± spathulate to oblong-elliptic in outline, 10(-12) mm long × 6 mm wide, apex 2-toothed, tube 2 mm long. Disc florets perfect, but either hermaphroditic or functionally male, 40-50+, corolla actinomorphic with narrow cylindrical tube 6 mm long, throat cylindrical-funnelform 1 mm long × 1 mm wide; corolla lobes 5, acute, dark in colour, reflexed, tiny oil dots sparse in the inner side; style 5-6 mm long, stigma branches coiled, linear subulate ± 1.5 mm long, surpassing corolla lobes, short pubescent and papillate outside; stamens 5, 4 mm long, surpassing corolla lobes, but not stigma branches, with stiff rhombic-shaped terminal appendage at level of corolla lobes, thinly glandular, sub-auricular at base, filaments distinct, ± 2 mm long. Cypselae monomorphic (but some larger than others), 4-5 mm long × 4(-3) mm wide, laterally compressed, obovoid in outline, with a broad shallow apical cleft, margins densely silky villous (immature), at maturity margins with a thin chartaceous edge <1 mm, faces glabrous, black, smooth in texture, epappose.

Type.

Mexico: Baja California Sur: municipio de La Paz, zona de Protección de Flora y Fauna Balandra, colina adyacente al estacionamiento del Balneario Balandra. 24.324894°N, - 110.326251°W, ca. 60 m de elevación, laderas rocosas, 19 de Enero 2020, J.L. Leon-de la Luz 13007 (holotype: HCIB 31869, isotypes to be distributed UC, MEXU, SD) .

Paratypes - Mexico. Baja California Sur: Municipio de La Paz, cerca El Tecolote 6 km al N de Puerto Pichilingue. 24.2000°N, - 110.23300°W, ca. 7 m de elevación, 2 de Septiembre 1994, M. Domínguez León 762, HCIB 4740. Municipio de La Paz , Cerro Balandra, 2 km al N de Puerto Pichilingue. 24.323500°N, - 110.326700°W, 18 m de elevación, 20 de Enero 1995, M. Domínguez León 959, HCIB 4739. Municipio de La Paz , ladera rocosa cerca de El Pulgero. 24.346067°N, - 110.270051°W, 8 m de elevación, 20 de Enero 1995, J.L. León de la Luz 7517, HCIB 5127. Bahia de La Paz , Sierra Riolítica, Cerro Manglar El Merito. 24.301191°N, - 110.324712°W, 28 m de elevación, 22 de Noviembre 2013, J.L. León de la Luz 11891, HCIB 624. Bahia de La Paz , Zona de Proteccion de Flora y Fauna Balandra, Cerro adjunto al Tecolote. 24.3406634°N, - 110.304868°W, 15 m de elevación, 10 de Octubre 2019, J.L. León de la Luz 12900, HCIB 31868. Municipio de La Paz , Playa El Tecolote, cerrito al extremo Este de la playa. 24.341095°N, - 110.304525°W, 16 m de elevación, 1 de Octubre 2022, J. L. León de la Luz 13125 .

Etymology.

Balandra Beach is an emblematic place near La Paz, the capitol city of Baja California Sur, which is considered by many to be one of the most scenic beaches in all of Mexico.

Distribution and ecology.

This species is known only from the hills of the Balandra/Pichilingue area, where a total of 20 documented individuals occur over an area of no more than 500 hectares. E. balandra grows on coarse gravelly soils to bare rocky outcrops on the slopes of the hills. Some plants were documented on gravelly soil in the immediate vicinity of the seashore. Some insect visitors observed actively pollinating the plants were bees ( Apidae ), hoverflies ( Syrphidae ) and wasps ( Hymenoptera ).

Conservation status.

E. balandra is a new species described from an area that is an important touristic destination. The area currently faces pressure due the growing influx of local and international visitors, which spend time either at the beaches or hiking in the hills. Thus far, 20 individuals of E. balandra have been found. Taxonomic resolution of this new species lays the foundation for more targeted surveys to illuminate its population status, environmental restrictions and threats from anthropogenic pressures. Until more information about its status is collected, E. balandra should be categorised as data deficient (DD) under the IUCN current guidelines for Categories and Criteria ( IUCN Standards and Petitions Committee 2022). However, we expect that, once surveyed, this rare plant would qualify as having a very restricted distribution with high plausibility of being threatened with extinction (VU). More information and material should be gathered and the environmental authority of Mexico (SEMARNAT) should consider managing visitation within the immediate area as a precautionary measure.

Phenology.

E. balandra is herbaceous with a woody taproot. Leaves appear to grow opportunistically in response to late summer, autumn or early winter rainfall. The peduncle and its capitulum, or head, reach anthesis some 20-30 days after a heavy rainfall, when foliar growth ceases. Some inflorescences and fruits could be present in the early autumn after summer rainstorms, but vigorous flowering also occurs if enough early winter rain is present.

Evolutionary affinities.

To understand phylogenetic affinities of E. balandra , we used the Internal Transcribed Spacer (ITS) and External Transcribed Spacer (ETS) of nuclear ribosomal DNA. Both spacers are commonly employed in fine-scale studies of angiosperm relationships and this region has been used for understanding relationships amongst closely-related species within Enceliinae ( Fehlberg and Ranker 2007). We extracted DNA and amplified both regions from leaf material sampled from the type specimen. When compared with publicly available DNA sequence data using the BLAST algorithm, our sequences for ITS and ETS were matched to members of Encelia with high percentage identity (ITS: 98.3% match with Encelia frutescens A. Gray MF963851.1; ETS: 98.34% match with Encelia farinosa var. farinosa A. Gray DQ383844). The ML phylogeny output from RaxML placed our study species within the genus Encelia with high support, confirming conclusions drawn from morphological evidence as shown in Fig. 4 . Within Encelia , E. balandra occupies an early diverging branch of the frutescens clade with moderate bootstrap support.

GenBank accession numbers.

ITSMZ892906, ETSMZ576216.

Figures

Figure 2. Line drawings of Encelia balandra sp. nov. A mature branch with basal leaves and terminal peduncle B strigulose indumentum on leaves, also present in peduncles and phyllaries; also, leaf venation pattern C ray floret, neuter D cypsela, note a broad shallow apical cleft and glabrous faces, epappose E palea F disc floret showing silky villous margins of immature achene G anther cylinder, opened out H immature achene / cypsela and style. Art by Danira Leon C, based on material from JLLL 12900.

Figure 3. Photographs of Encelia balandra illustrating habitat and morphological characters of the capitula and cypselae A habitat on the rocky hills north of Playa Balandra B abaxial view of capitulum showing phyllaries C adaxial view of capitulum showing ray limbs and paleae enfolding disc florets D cypselae. Photos by ILM.

Figure 4. Phylogenetic position of Encelia balandra. Maximum Likelihood phylogeny of subtribe Enceliinae, based on a combined data matrix of Internal Transcribed Spacer (ITS) and External Transcribed Spacer (ETS) regions derived from the molecular phylogenetic study of Fehlberg and Ranker (2007), with the addition of Encelia balandra (bold and inset photograph). Bootstrap values along branches indicate statistical support for relationships and were generated using 1000 bootstrap replicates in RAxML using a GTRCAT molecular substitution model (Stamatakis 2014).