Lepanthes attenboroughii Baquero & Yeager. A. Flower 2022, sp. nov.
Creators: name: Yeager, Justin
name: Iturralde, Gabriel A.
name: Horna, Luis Ocupa
name: Baltazar, Abel Huayta
name: Baquero, Luis E.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Asparagales
Orchidaceae
Lepanthes
Lepanthes attenboroughii

description: Lepanthes attenboroughii Baquero & Yeager, sp. nov. (Figures 1–4)
Type: — PERU. Pasco: Santa Cruz, km 10 of the Oxapampa highway to Villa Rica, 2030 m, flowered in cultivation in Huaytianum Center for the Study and Conservation of the Orchid, 23 March 2022, Ocupa & C. Martel 305 (holotype: USM!).
Lepanthes attenboroughii is similar to L. caprimulgus in both having striped, deeply cupped flowers but it can easily distinguished from the later in having the rounder flowers in an oblique, leaning position with rounder sepaline cups (vs. vertical long-tubular, shaped as a peanut fruit with oblong flowers with a waist near the middle), the broadobovate, shallowly concave, dorsal sepal with an acute apex (vs. the oblong dorsal sepal, deeply concave at the obtuse, rounded apex with and apiculum), the free-apical portion of the synsepal, slightly shorter than the cupped-basal portion (vs. the considerably shorter free-apical portion of the synsepal, about one third of the total length of the synsepal) the transversely spatulate petals with similar in shape and size upper and lower lobes (vs. transversely oblong, asymmetric petals with elongated lower lobes) and an oblong, concave lip (vs. broadly ovoid).
Description:— Plant epiphytic, caespitose herb up to 9 cm long. Roots slender ca. 1.3 mm in diameter. Ramicauls erect, slender, 3.0–8.0 cm long, enclosed by 5–8 scabrous, lepanthiform sheaths. Leaf green, erect, coriaceous, elliptical, subacute to obtuse, mucronate, 20–28 × 11–13 mm wide, the base cuneate into a petiole 2.0– 2.5 mm long. Inflorescence 1 to several few flowered racemes, borne on base of the leaf, with successively and distantly distributed pendant, obliquous-leaning flowers, 1.1–1.5 cm apart, borne far beyond the leaf -the first flower is borne 9 cm beyond the apex of the leaf-, by a slender, glabrous, drooping peduncle 5.0– 8.5 cm long, with only one open flower at a time per peduncle. Floral bracts minute muricate, 2 mm long. Pedicel green, glabrous 2.0 mm long. Ovary costate, glandular mainly at the crests 2.5–3.0 mm long. Sepals yellow, with sanguineous-red stripes, carinate and distantly pilose abaxially, the dorsal sepal broadly obovate, shallowly concave longitudinally, acute, acuminate, 19 × 10 mm unexpanded, 7-veined, at the base connate 10 mm to the lateral sepals, to form an inflated, saccate, rounded sepaline cup, the free portion of the sepal with a erose, reflexed margin at the apex. The lateral sepals connate 9.0– 10 mm at the base to form a longitudinally concave, bifid lamina 10.5 × 10.5 mm unexpanded, 6 veined, with the deflexed, free for 6.0 mm, orange, triangular, acute, and papillose apices. Petals yellow, transversely, shortly spatulate, minutely papillose, 1.1 × 0.5 mm, with a round, obtuse tip at the apex. Lip yellow, free, oblong, concave, longitudinally sulcate, the margins thickened, apiculate, 0.7 × 0.7 expanded. Column yellow, terete, erect, 1.7 mm long. Anther dorsal, anther cup white. Stigma apical, ridged. Pollinia 2, yellow, pyriform. Capsule not observed.
Distribution and Ecology:— Lepanthes attenboroughii has been collected as an epiphyte in cloud forest at around 2000 m elevation in Pasco, central Peru (Figure 5). The authors considered not including Ecuador within the confirmed distribution of L. attenboroughii because the locality of the allegedly found plants of this species by H. Medina (pers. com.) could not be verified before and during this study. With more than 20 years of research in the area where plants of L. attenboroughii were supposedly collected by Hugo Medina of Ecuagenera (even with coordinates provided by him) but lacking a voucher specimen, no fertile or infertile plants have been found by the authors or anyone else. Considering the distribution of the confirmed collections of L. caprimulgus and L. attenborougii from Peru done by two of the authors, we find it improbable that L. attenboroughii could be found growing in north-west Ecuador, close to the border of Colombia. If plants of L. attenboroughii would eventually be collected in Ecuador, the most probable locality would be the south-east Andes or the Cordillera del Condor (south-east of Ecuador), both areas close to Peru.
Conservation status:— Because the plants have been observed in situ on a few occasions, little information on the real conservation status is currently available. According to IUCN criteria, L. attenboroughii should be considered as Data Deficient (DD) until the status of natural populations is assessed. Nevertheless, L. attenboroughii has propagated in vitro extensively, making it abundant ex situ in both private and public collections.
Etymology:— Lepanthes attenboroughii is named in honor of Sir David Attenborough whose life has been dedicated to educating and inspiring generations of naturalists and conservationists, and most recently been a vocal advocate with his fervent call to action in response to global climate change.
Additional specimens examined (paratype):—Flowers in spirits of plant purchased from Ecuagenera. L. Baquero LB-3141 (QCNE)
Additional studied specimen of L. caprimulgus: — PERU. Huánuco: Leoncio Prado Province, Hermilio Valdizan District, from a forest patch near caserío Margarita, 1713 m, L. Ocupa 281 (USM!).
Taxonomic Discussion: —A long-term cultivated specimen from a private collection closely resembling the type of L. caprimulgus and undoubtedly identified as such was studied (Figs. 2–4). Additionally, wild plants from Huanuco, Peru were photographed and studied, and were confirmed to be L. caprimulgus when compared with the original description and holotype (Luer 1976) (Figure 5). When all available photographic material was consulted in Google Images and Flickr.com under the search for “ Lepanthes caprimulgus ” about 8 out of 10 photos belonged to L. attenboroughii and only 2 out of 10 photos belonged to L. caprimulgus. This supports the fact that misidentified L. attenboroughii is more common in cultivation and better documented than L. caprimulgus. For both species, phenotypic variations of the flowers could be observed nevertheless, no intermediate shaped flowers between L. caprimulgus and L. attenboroughii were observed.
Lepanthes attenboroughii is most similar to L. caprimulgus with which it shares several features such as the conspicuously cupped, and stripped flowers, with the petals, lip and column hidden inside the sepaline cup.Additionally, both species have five veins on their dorsal sepals, and eight veins in the synsepal, more than most species in the genus. Nevertheless, morphological features readily distinguish both species. Some morphological, consistent features help to immediately distinguish both species like the position of the flowers (with leaning flowers, in more horizontal position of L. attenboroughii compared to the flowers in vertical position of L. caprimulgus) and the rounder flowers of L. attenboroughii compared to the “peanut shaped”, tube-like flowers of L. caprimulgus. Nevertheless, other morphological characteristics could have a direct relationship regarding specificity of pollinators with evolutive repercussions (Figures 1–4). In Lepanthes the specificity of pollinators would be one of the most important factors of evolutive divergence between species (Blanco &. Barboza 2005). The petals of L. caprimulgus are substantially wider with a lower elongated lobe that extents below the lip (Figure 2) compared to the symmetric petals with shorter lobes in L. attenboroughii (Figures 1–4, 6). The lip, neverthelss is larger and longer with a marked apiculus at the apex in L. attenboroughii different to the smaller, broadly ovoid lip of L. caprimulgus (Figures 2 and 6). Also, the rounder flowers of L. attenboroughii always bear a longer apical portion of the reflexed lateral sepals which extend far almost reaching the base of the flower. This portion of the synsepal is slightly shorter than the fussed basal portion (Figures 1–4 and 6). In L. caprimulgus, in the other hand, the free, reflexed portion of the lateral sepals barely reach about one fourth of the total length of the sepaline cup (Figures 2–4 and 6). Considering the lack of intermediate shapes between the external and internal structures of the flowers from both species and 180 km between the confirmed populations (with no intermediate populations in between), of L. attenboroughii and L. caprimulgus we consider that these are two lineages with their own population evolving independently. Incidentally, L. attenboroughii was illustrated years ago by Miguel Alcántara in Bennet´s Icones Orchidacearum Peruvianum (Bennett & Christenson 1998) (Figure 6). This precise illustration clearly shows the flowers in an almost horizontal position, the synsepal inflated, deeply cupped with the chef’s hat-shaped petals and the oblong and concave lip, when compared to Luer´s illustration of L. caprimulgus (Luer 1996: permissions granted by Missouri Botanical Garden Press, St. Louis) which features tube-shaped vertically oriented flowers. Both illustrations are well representations of both species when disected flowers and photographs of both species were compared (Figures 2–4 and 6).
Lepanthes caprimulgus although belonging to the subgenus Marsipanthes has recently shown to be genetically related to other Peruvian species like L. martinae or L. nycteris and not closely related to L. ribes (a similar looking species belonging to the subgenus Marsipanthes) which could indicate that the subgenus may be paraphyletic (Bogarín et al. 2019). Further genetic sampling including Lepanthes attenboroughii and more coverage across the genome would be beneficial to further resolve phylogenetic relationships of this group.
description: Published as part of Yeager, Justin, Iturralde, Gabriel A., Horna, Luis Ocupa, Baltazar, Abel Huayta & Baquero, Luis E., 2022, A Remarkable new Lepanthes (Orchidaceae: Pleurothallidinae) hidden in plain sight, pp. 285-294 in Phytotaxa 560 (3) on pages 286-291, DOI: 10.11646/phytotaxa.560.3.3, http://zenodo.org/record/7042641