Lepanthes skeleton is a small, tufted epiphytic orchid with slender roots and very slender, erect secondary stems (ramicauls) 3–5.5 cm long, enclosed by ten to thirteen nearly glabrous lepanthiform sheaths with dilated ostia — the funnel-shaped, fringed sheaths characteristic of the genus, here unusually numerous. Each ramicaul bears a single erect, coriaceous leaf, reticulate beneath, elliptical and acute, 15–18 mm long and 7–8 mm wide, the base cuneate into a 1–1.5 mm long petiole.

The inflorescence is a congested, long-pedicellate, distichous, successively many-flowered raceme up to 5 mm long, borne behind the leaf by a filiform peduncle 10–15 mm long; the floral bracts are 1 mm long and sparsely spiculate; the pedicels are 5–6 mm long; the ovary is curved, 1 mm long. The sepals are yellow, glabrous, denticulate on the margins and on the keels (carinae); the dorsal sepal is ovate, acute, concave, 3.75 mm long and 2.5 mm wide unexpanded, 3-veined, connate to the lateral sepals for 0.5 mm; the lateral sepals are connate to near the apex into an ovate synsepal 3.5 mm long and 2.25 mm wide, each 2-veined. The petals are minutely pubescent and tripartite — divided into three narrowly linear segments — the upper segment yellow, the middle segment yellow, 1.25 mm long, the lower segment orange, 1.5 mm long. The lip is red and pubescent, bilaminate, the blades narrowly oblong as thickened margins of broad cuneate connectives, 1.2 mm long; the body is broad, connate to the column above the base; the appendix is large, narrowly triangular, pubescent, 0.8 mm long, and protrudes downward. The column is terete, 1.5 mm long, with a dorsal anther and a ventral stigma.

Flower characteristics at a glance: the flower is small (sepals 3.5–3.75 mm long) but unusually expressive, with broad yellow sepals, a red lip with a downward-pointing pubescent appendix, and three thread-like petal segments (two yellow, one orange) that splay out from between the sepals. Behind the leaf, the long filiform peduncle and the many pedicels of past, present and future flowers along the raceme axis give the inflorescence its characteristic skeletal silhouette.

The morphological characters described here follow Luer & Escobar (1984); the description is reproduced with minor modernization by Luer & Thoerle (2012) in Icones Pleurothallidinarum XXXII.

The published literature describes Lepanthes skeleton as an epiphyte of Andean cloud forests in northern Antioquia, recorded between approximately 1,850 m and 2,700 m in the Yarumal sector and adjacent localities (Luer & Escobar, 1984). The protologue cites collections from cloud forest along Río El Oro, from a forest remnant above El Cedro, and from cloud forest near Quebrada El Oro — all on woody vegetation in mature forest.

At La Honda the species has been observed in mature secondary forest, growing as aggregated clusters on twigs, branches and trunks in well-shaded humid microsites within the forest interior. Where it occurs it is gregarious — multiple plants on the same branch or in close proximity on neighbouring substrates — rather than appearing as isolated individuals. This differs from the local habit of Lepanthes reticulata, which at La Honda is observed only as scattered solitary plants despite the two species sharing a Yarumal type locality.

Lepanthes skeleton is endemic to Colombia, known from the department of Antioquia. The holotype was collected at Yarumal, above Quebrada El Oro, at 1,850 m (14 February 1984; R. Escobar & E. Valencia 3231, Holotype MO; isotypes COL, JAUM, SEL; illustrated as C. Luer 9506) and published by Luer & Escobar (1984) in the American Orchid Society Bulletin. Additional collections cited in the protologue come from cloud forest along Río El Oro at 2,700 m, from a forest remnant above El Cedro at 2,000 m, and from cloud forest near Quebrada El Oro at 1,850 m — bringing the published elevation range to approximately 1,850–2,700 m.

Notably, the same field expedition on 14 February 1984 that yielded the L. skeleton holotype also yielded a paratype collection of Lepanthes reticulata (R. Escobar & E. Valencia 3226, at 1,820 m in the same Quebrada El Oro sector). The two species — both described by Luer & Escobar in American Orchid Society Bulletin 53 (1984) and both endemic to Antioquia — are therefore sympatric at the type locality, separated by sequential field numbers and only a short walk along the same creek.

The La Honda record extends the known range of L. skeleton substantially southward, by approximately 100 km along the Cordillera Central, into the eastern-Antioquia massif at El Carmen de Viboral. As with L. reticulata, all of the collections cited in the protologue lie within the northern segment of the cordillera around Yarumal; the La Honda population represents, to our knowledge, an extension of the known range into the eastern-Antioquia subregion. The verification of this identification by a Colombian Lepanthes specialist is a matter of editorial importance for this sheet, and the record is presented here pending such verification.

Flowering has been observed in La Honda, with single open flowers at the tip of the long-pedicellate raceme and many additional pedicels along the same axis bearing past or future flowers. Because the inflorescence opens its many flowers successively rather than simultaneously, an individual plant can present a bloom over an extended period; what cannot be reliably characterised from current observations is whether peak flowering at La Honda is restricted to a particular part of the year. Systematic observation across a full annual cycle would be required to describe the phenology of the local population.

Recognition of Lepanthes skeleton rests on the inflorescence: a long, slender peduncle (10–15 mm) borne behind the leaf rather than on top of it as in most Lepanthes, with a raceme axis from which 5–6 mm pedicels emerge along the length, giving the impression of a curved, ribbed skeleton. A single flower at any time sits at the tip or along the axis: yellow sepals (the laterals fused into a synsepal almost to their apex), a red pubescent lip with a downward-pointing triangular appendix, and tripartite petals divided into three thread-like segments — two yellow, one orange. The combination of long-pedicellate, behind-the-leaf raceme + tripartite filiform petals + red lip is, in the field, very recognisable.

Lepanthes skeleton is placed in Lepanthes section Lepanthes, subsection Lepanthes, series Mucronatae (Luer, 1996) — the same series as Lepanthes mucronata, already documented in this project; the two species share the section-level vegetative habit but differ markedly in the structure of the inflorescence and in floral colour. In the original 1984 diagnosis the species is compared to Lepanthes heptapus, from which it is distinguished by broader leaves, distichous (rather than secund) racemes, almost completely connate (rather than free) lateral sepals, and a thick lip appendix shorter than the lip blades (rather than a longer filament). The genus Lepanthes as a whole is diagnosed by the lepanthiform sheaths on the ramicauls.

Lepanthes skeleton has not been evaluated globally on the IUCN Red List (status NE, Not Evaluated, as of the date of this sheet). At the national regulatory level in Colombia, the species is not listed in Resolución 0126 de 2024 of the Ministry of Environment; it is therefore not classified as threatened under current Colombian environmental law.

"Not Evaluated" is not a statement that the species is safe — it is a statement that no formal assessment has been made. Miniature orchids of the genus Lepanthes, including species not yet formally assessed, remain subject to poaching for specialist collectors, and populations can be depleted by collection far faster than an assessment system can respond. Lepanthes skeleton is also narrowly distributed in cloud forest along the Cordillera Central in Antioquia — a habitat under sustained pressure from land-use change, fragmentation and conversion. The La Honda population is gregarious where it occurs, which makes it visually conspicuous on a small number of branches; this kind of aggregated habit is at once an advantage for documentation and a vulnerability, since a single disturbance event at the host substrate can affect a disproportionate share of the local population.

For these reasons, the specific location within La Honda where L. skeleton has been documented is not published, and elevation data are redacted from this sheet. Requests for further locality detail from researchers or conservation practitioners with a legitimate scientific or institutional purpose may be directed to [email protected].