Lepanthes debilis is a small, epiphytic, caespitose orchid with slender roots that are nonetheless thicker than the ramicauls themselves — an unusual proportion that gave the species its name. The ramicauls are very slender, weak, and suberect, 3–6 cm long, enclosed by 7–9 thin, tightly fitting lepanthiform sheaths with minimally dilated ostia and microscopically scabrous margins. The leaf is thinly coriaceous, more or less spreading, ovate, 25–32 mm long and 11–16 mm wide, with the apex acute and long-acuminate and prominently tridenticulate. The base is cuneate, contracted into a 0.5 mm-long petiole.

The inflorescence is a congested, distichous, successively many-flowered raceme up to 6 mm long, borne on top of the leaf by a filiform peduncle approximately 5 mm long; floral bracts 0.75 mm long, lightly muricate; pedicels 1–1.25 mm long; ovary 1 mm long. The sepals are translucent yellow, glabrous, with smooth margins. The dorsal sepal is broadly ovate, obtuse, 2.5 mm long and 2.25 mm wide, 3-veined, fused to the lateral sepals for 0.5 mm. The lateral sepals are ovate, oblique, connate 1.5 mm into a broadly ovate synsepal 2.5 mm long and 2.5 mm wide, with the apex shallowly bifid, each 2-veined.

The petals are orange, bilobed, 1 mm long and 3.2 mm wide, long-ciliate and long-pubescent medially, short-pubescent toward the apices. The upper lobe is obliquely subquadrate, with the inner angle of the obliquely truncate apex obtuse and the outer angle acute; the lower lobe is longer, narrowly triangular, acute and lightly incurved. The lip is orange, bilaminate, with the blades oblong and rounded ends, 1.6 mm long, membranous, minutely ciliate; the connectives narrow, oblong, fused from below the middle of the blade; the body transverse, fused to the base of the column; the appendix narrowly scaphoid with involute margins, pubescent, lying beneath and between the lobes of the stigma. The column is 1 mm long, with the anther dorsal and bearing an elongated rostellum overlying the appendix; the stigma is ventral.

The morphological characters described here follow Luer & Escobar (1988), as reproduced in Luer & Thoerle (2012) in Icones Pleurothallidinarum XXXII.

The published literature describes Lepanthes debilis as an epiphyte of cloud forest in the eastern Antioquian Cordillera Central. The protologue (Luer & Escobar, 1988) cites the holotype and paratype localities at elevations between 1,850 and 2,600 m, all within the municipalities of El Carmen de Viboral and Guatapé in eastern Antioquia.

In La Honda, L. debilis has been observed between approximately 2,200 and 2,500 m, where the species occurs as small plants on mossy twigs and on the surfaces of mossy rocks. The occurrence on rock surfaces is notable: among the Lepanthes documented in this book, only L. cerambyx has been recorded with a similarly rupicolous habit, making L. debilis the second rupicolous Lepanthes in the project. The microhabitat — wet, moss-covered twigs and adjacent rock surfaces in the understorey of mature montane forest — places L. debilis among the suite of miniature pleurothallids that depend on the persistent humidity and moss cover of intact cloud-forest microsites.

Lepanthes debilis is endemic to Colombia and, more specifically, to a tight cluster of localities within eastern Antioquia (POWO, 2026; Luer & Thoerle, 2012; Idárraga-Piedrahita et al., 2011). The species has not been documented outside its narrow Antioquian range to date.

The protologue (Luer & Escobar, 1988) cites the holotype from El Carmen de Viboral, in the Alto de San Lorenzo at 2,600 m — collected by R. Escobar, C. Dodson and P. Dodson in September 1984 (holotype JAUM, isotype MO) — together with two paratypes: an offset of the holotype illustrated by C. Luer (illustr. 11531), and a second paratype from Guatapé, Vereda Santa Rita, Finca Montepinar at 1,850 m, collected by Restrepo in October 1986 (MO).

The La Honda record at 2,200–2,500 m sits within the elevational band documented for the species and within the same municipality (El Carmen de Viboral) as the holotype locality — making L. debilis the first species documented in this book whose type locality and La Honda are in the same municipality. La Honda lies in the same eastern-Antioquian Cordillera Central corridor that connects the San Lorenzo and Guatapé localities of the protologue, and the La Honda record extends the documented occurrence of L. debilis within El Carmen de Viboral itself.

Flowering has been observed at La Honda. The available data are not yet sufficient to characterise local phenology with precision; systematic observation across a full annual cycle would be required to identify flowering peaks or quiescent periods. The protologue raceme architecture — congested, distichous and successively many-flowered — implies that fertile plants may bear ripening capsules and developing flowers concurrently, a pattern characteristic of the genus.

Recognition rests on the combination of vegetative habit and floral architecture. Vegetatively, the very slender, weak ramicauls (3–6 cm) that — as Luer himself observed — are barely able to support the long-acuminate, tridenticulate leaves give the species its diagnostic vegetative impression and the source of its name. The leaves are thinly coriaceous and noticeably long-acuminate, with the prominently tridenticulate apex visible as a small three-toothed point at the leaf tip.

Florally, the diagnostic features are the congested, distichous raceme borne on top of the leaf on a short filiform peduncle; the translucent yellow sepals, of which the dorsal is broadly ovate and the laterals are fused into a broadly ovate, shallowly bifid synsepal; and the orange, bilobed, long-ciliate petals with their distinctive long-pubescent medial zone and their subquadrate upper lobe contrasting with the narrowly triangular, longer lower lobe. The lip is orange, bilaminate, with oblong membranous blades and a narrowly scaphoid pubescent appendix. Luer's own diagnostic note links L. debilis to Lepanthes mucronata and its allies — the membranous lip blades are reminiscent of those of L. mucronata — but L. debilis differs in lacking a medial lobule on the petals that L. mucronata possesses.

Lepanthes debilis 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. L. debilis is a narrow Antioquian endemic, with all known localities concentrated in eastern Antioquia at elevations between approximately 1,850 and 2,600 m. The species depends on the persistence of mature montane forest and intact moss-bearing twig and rock substrates within that elevational band. Eastern Antioquia has experienced sustained pressure from agricultural expansion, road construction, and forest fragmentation; locally, persistence of L. debilis depends on the continuity of the mature forest matrix that maintains the cool, humid, moss-rich microhabitat the species requires.

For these reasons — and to maintain consistency with the locality-redaction practice applied to the other Lepanthes sheets in this book — the specific location within La Honda where L. debilis has been documented is not published, and precise elevation data beyond the approximate 2,200–2,500 m tier 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].