Androlepis najarroi Ramírez-Díaz & I. Ramírez, 2020

Ramírez-Díaz, Claudia J., Ramírez-Morillo, Ivón M., Romero-Soler, Katya J., Carnevali, Germán, Pinzón, Juan P. & Zizka, Georg, 2020, A new species of Androlepis (Bromelioideae; Bromeliaceae), endemic from southern Megamexico, Phytotaxa 430 (4), pp. 277-286 : 279-281

Androlepis najarroi Ramírez-Díaz & I. Ramírez , spec. nov. ( Figure 1 ).

Diagnosis: —This species is morphologically similar to Aechmea lueddemanniana , but is distinguishable by its persisting peduncle bracts (vs. deciduous), which are bright red (vs. light pink), inflorescence branched only at the base (vs. entirely branched), unisexual flowers (vs. bisexual) and apically divided filament in two appendages (vs. filaments without appendages). It is different from other Androlepis species due to its smaller vegetative size (leaves 45‒60 cm vs. exceeding 100 cm), shorter inflorescence (<50 cm vs> 120 cm long) with the peduncle with a dense indument of stellate trichomes (vs. covered with a white, dense to subdense indumenta), and leaves of a softer texture (vs. coriaceous)

Type: — MEXICO. Chiapas: Municipio Berriozábal, 1.3 km W of finca El Suspiro (6 km in a straight line NW of Berriozábal), 16º 50’ 56.5’’ N, 93º 18’ 39.5’’ W, 1200 m, collected 13 November 2017, fl. cult. 14 March 2019, C. J. Ramírez-Díaz 850 ♂, K. J. Romero-Soler & F. Hernández-Najarro (holotype: CICY, isotype MO).

Plant epiphytic, funnelform rosulate, acaulescent, flowering up to 50 cm tall, the base forming a central sub-cylindrical tank 4‒6 cm in diameter and 14‒15 cm deep. Leaves 45‒60 cm long, ca. 15 in number, thin coriaceous, densely white lepidote below, laxly covered with translucent trichomes above; sheath ovate, 15 × 6‒10 cm, pale green, slightly wider than the blades; blade strap-shaped, acute or rounded and apiculate, 30‒45 × 4‒7 cm, green, becoming reddish with solar exposition, margins armed with antrorse fine spines; spines 1.2‒1.5 × 1 mm, 3‒5 mm apart. Inflorescence a terminal panicle, erect, cylindrical to slightly pyramidal in contour, once-branched, with 6‒12 basal branches but simple in the middle and apical portion, 40‒50 cm long, the fertile portion 15‒20 cm, exceeding the spreading rosette by 15 cm; branches basal ones 2.5‒4.5 × 1‒1.5 cm; peduncle terete, 22‒40 long, 3‒5 mm in diameter, green, with a dense indument of stellate trichomes, central internodes 3‒5 cm long; peduncle bracts 2‒3 times longer than the internodes, the lower ones clasping the peduncle, persisting, membranaceous, nerved, bright red, erect, margins entire, the central ones 5‒8 × 0.9‒2 cm, translucent-lepidote; primary bracts the lower ones spreading to pendulous, persisting, the basal ones 3‒3.5 times longer than the axillary branches, 5.5‒7 × 0.8‒1.8 cm; apex acute, translucent-lepidote; floral bracts narrowly triangular to filiform, as long as the pedicels, 1.5‒3 × 0.2‒0.4 mm, yellowish, with stellate trichomes scattered on both sides. Flowers unisexual (only functionally staminate flowers observed), 9–12 × 2.8–3.2 (–3.8) mm, stigmas absent or, when present, then atrophied; pedicels 2‒6 mm long, green, slightly elongated and thickened in fruit, indument as on the peduncle; sepals asymmetric, 4‒4.5 × 2.5‒3.5 mm, the broad lateral marginal wing never exceeding the apical mucro, with 5‒10 prominent nerves; margins hyaline and entire, apex mucronate with a 1‒1.4 mm long mucro; corolla tubular, actinomorphic; petals spatulate, cucullate, 8‒8.6 mm long, 3.2‒4 mm wide, 1.8‒2 mm at the base, purple at anthesis, turning pink-red after anthesis, glabrous, margins erose distally, entire elsewhere; petal appendages two, produced 1.8‒2 mm from the petal base, 1.1‒1.3 mm long, sacciform, lacerate; stamens included; filaments transversally sub-quadrangular, antepetalous ones basally adnate to the petals for 1/3 of their length, 7‒8 × 0.2‒0.4 mm, distally extended and divided above the connecting point with the anthers, in two lobulated appendages not exceeding the anthers; anthers oblongoid, dorsifixed at the middle, 2‒2.5 × 0.4‒0.7 mm; pollen solitary, 37‒38 × 27‒28 µm, biporate, with foveolate exine; ovary of the pistiloid ovoid, 10‒14 × 5‒8 mm, with a few apparently sterile ovules; stigma of the pistiloid apparently atrophied, without a distinct stigmatic surface. Fruits ellipsoid, 1‒1.2 × 0.5‒0.7 cm, scattered lepidote; seeds not observed.

Additional specimens examined: — MEXICO. Chiapas: Municipio Berriozábal, 1.3 km W of finca El Suspiro (6 km in a straight line NW of Berriozábal), 16º 50’ 56.5’’ N, 93º 18’ 39.5’’ W, 1200 m, 13 November 2017, C. J. Ramírez-Díaz, K. J. Romero-Soler & F. Hernández-Najarro 824 ♂ ( CICY) ; 10 km N de Berriozábal , 2000 m, 15 May 1989, E. Martínez S. & M. A. Soto, M-24208- A ♀ (fruiting, MEXU!) ; cerca de Finca El Suspiro, 11 January 1958, F. Miranda 7645 ♀ ( MEXU!) ; Pozo Turipache , 5 November 2004, M. G. Díaz M. 286 ( CHIP!) ; 9 km W of Berriozábal, Vistahermosa , 11 September 2005, C. R. Beutelspacher 212 ♂ ( HEM!) ; Municipio San Fernando, de Tuxtla Gutiérrez a Montecristo , 17 November 1949, F. Miranda 5696 ♂ ( MEXU!) ; Municipio Siltepec , cerca de El Rodeo, 1800 m, 28 April 1964, E. Matuda 37402 ♀ (fruiting, MEXU!) . HONDURAS. Copán: Municipio Nueva Arcadia, La Meseta, Cerro Azul National Park , 1440 m, 9 February 1992, H. Thomas & D. Mejía 219 ♂ ( EAP!, TEFH!, USF!) .

Distribution and habitat: — Androlepis najarroi is known from six collections in Berriozábal, Siltepec, and San Fernando municipalities, Chiapas, Mexico, and from one additional locality in the Copán Department of Honduras. It is distributed along a more or less continuous mountain range extending across the Chiapas Highlands Biogeographic province and the southeastern limits of the Veracruzan province ( Figure 2 ). The new species grows in very humid habitats, in the upper part of the canopy of tropical and cloud forests ( Figure 1A ), at 900‒2000 m elevation. At least at the type locality, the species grows in sympatry with Aechmea lueddemanniana .

Etymology: —This species is named after Francisco Hernández-Najarro, botanist and collector of the Chiapas flora, who has guided many botanists through this extraordinarily biodiverse region and has contributed considerably to the knowledge of Neotropical plant diversity.

Phenology: —The reproductive biology of this species is unknown in almost all aspects. The specimen collected at the type location exhibited only male flowers whereas an additional plant flowered under cultivation produced flowers with a poorly developed stigma ( Figure 1I ) and an ovary lacking ovules. Two specimens exhibit fruits at different stages of maturity (E. Matuda 37402 and E. Martínez S. & M.A. Soto 24208-A); however, functionally female flowers have not been observed. Specimens examined indicate a flowering period from September to November although under cultivation it has flowered during March. Fruiting specimens have been collected from January through May. With the purpose of understanding the ecological and evolutionary roles that dioecy plays within the subfamily, it is necessary to evaluate other aspects of its reproductive biology, such as interactions with pollinators or population dynamics. This should be done not only for this species but also for populations of other sympatric Bromelioideae .

Conservation status: — Androlepis najarroi is known from seven collections from three locations in Chiapas, Mexico, and a disjunct location 300–400 km away, at La Meseta, Copán Department, Honduras. Based upon this, the EOO of this species is 24949.6 km ², and the AOO is 20 km ². According to the IUCN criteria, this species could be considered Vulnerable (V) because of the number of known populations (<10) and its AOO, which is in the lower range for this category (<2000 km ²). However, it is likely that other populations exist within the mountainous range of the Chiapas Highlands Biogeographic province ( Morrone 2014), which could function as a biological corridor for the species. The records of this species near the type location are within the La Pera Protected Natural Area, in the Berriozábal municipality of Chiapas (Gobierno del Estado de Chiapas 2006), and probably in the Sumidero Canyon Protected Natural Area, in San Fernando municipality. However, given the imprecise location of the latter, we cannot be sure of its occurrence in this protected area. In Berriozábal, epiphytes are locally extracted, mainly for ornamental purposes ( Martínez-Meléndez et al. 2016). However, the extraction of Androlepis najarroi has not been documented to this date, probably because most individuals grow in the higher strata of the canopy, where access is difficult ( Figure 1A ). This species may be more common than suspected and specimens of this taxon may be hiding in other herbaria (as well as in the field) passing for the phenotypically similar Aechmea lueddemanniana . The record from Honduras is from Cerro Azul National Park, a Protected Natural Area (30000 ha) whose buffer zone is greatly affected by agricultural activities, extensive cattle grazing, and urbanization ( Portillo et al. 2013, Coronado 2014). The remaining locations fall within unprotected (Chiapas, Siltepec, E. Matuda 37402), or imprecise locations (Chiapas, San Fernando, F. Miranda 5696). To improve the assessment of the conservation status, it is important to analyze the demography of the species, and the dynamics of its populations. Furthermore, it is important to assess the potential risks associated with a dioecious sexual expression, because the presence of both sexual morphs (and thus, at least two plants) and the intervention of pollinators, are strictly necessary ( Fernandes et al. 2018) for successful reproduction.

Figures

FIGURE 1. Androlepis najarroi Ramírez-Díaz & I. Ramírez. A. Habitat, the arrow points to an individual of An. najarroi. B. Androlepis najarroi blooming in habitat. C. Male flowers, notice the change of petal color after anthesis (from purple to pink). D. Male inflorescence. E. Longitudinal section of a male flower showing white anthers and purple petal appendages. F. Detail of petal appendages. G. Anther and distal appendages. H. Pollen. I. Atrophied pistil and stigma of male flower. Photographs: Claudia Ramírez-Díaz (A, C, D, E), Katya Romero-Soler (B) and Lilia Can-Itza (F, G, H, I). Abbreviations: An=Anther, Fi=Filament, Da=Distal appendages.

FIGURE 2. Distribution of Androlepis najarroi. A. Extent of Megamexico (between the red lines) in America. B. Biogeographical distribution of An. najarroi. C. Details of the distribution of the species in eastern Chiapas, Mexico, indicating the location of two natural protected areas.