Lepanthes tachirensis is a medium-to-large epiphytic orchid, caespitose, with slender roots and slender to stout erect ramicauls 5–35 cm tall, enclosed by 10–18 pale tan, glabrous lepanthiform sheaths with non-dilated ostia — a diagnostic departure from the ciliate, funnel-mouthed sheaths of many congeners. The single leaf is erect, coriaceous, narrowly ovate-elliptical and acute, 5–9 cm long and 1–2.5 cm wide, narrowing at the base into a petiole 3–4 mm long.

The inflorescence is a subcongested, distichous, few- to many-flowered raceme up to 30 mm long, borne behind the leaf on a slender peduncle 10–35 mm long; the floral bracts are 1.5–2 mm long, pedicels 1.5–2 mm, ovary 2–2.5 mm. The sepals are light yellow, light tan to white, glabrous, ovate and subacute, slightly acuminate, with minutely denticulate margins; the dorsal sepal is 4.5–5 mm long and 2–3 mm wide, 3-veined, connate to the lateral sepals for 0.5–1 mm; the lateral sepals are oblique, diverging a full 180°, 4.5–5 mm long and 2–3.75 mm wide, 1-veined, connate for 1 mm. The petals are orange with purple margin, transversely bilobed, 1–1.5 mm long and 3–4.5 mm wide; the upper lobe is oblong, subtruncate, with a prominent, fingerlike lobule on the inner apical angle that overlaps with the lobule of the paired petal — a defining character of the species; the lower lobe is smaller and triangular. The lip is usually red or purple, bilobed, with blades narrowly elliptical for the basal two-thirds, the apical third obtuse without forming a blade, the base narrowly obtuse, 2–2.25 mm long; the connectives are short and broadly cuneate, the body broad and connate to the base of the column, with a small, ovoid, pubescent appendix in the sinus. The column is 2 mm long, with a dorsal elongate anther and an apical stigma.

Flower characteristics at a glance: small (sepals 4.5–5 mm) but vividly coloured, with light-yellow sepals serving as a muted backdrop for the striking orange-and-purple petals; the paired fingerlike petal lobules overlap in front of the column to form the visual centre of the flower. Luer & Thoerle (2012) distinguish L. tachirensis from the similar Lepanthes speciosa of northwestern Ecuador by the wider spread of the denticulate lateral sepals (180° in tachirensis vs. ~90° in speciosa) and the oblong (not subcircular and concave) upper lobe of the petals.

The morphological characters described here follow Foldats (1968), as reproduced in Luer & Thoerle (2012) in Icones Pleurothallidinarum XXXII.

Lepanthes tachirensis is described in the published literature as an epiphyte of cloud forest and scrub forest at high elevations across the Northern Andes. The specimen records compiled by Luer & Thoerle (2012) document the species from cloud forest at 2,300–3,000 m across Colombia (Antioquia, Norte de Santander, Chocó, Quindío, Nariño), into the páramo-bordering scrub at Nariño (3,000 m), and across the border into Venezuela and Ecuador at comparable elevations. Luer & Thoerle describe it as "frequent and widely distributed" throughout this range.

In La Honda, L. tachirensis has been observed as an epiphyte in the forest interior of mature secondary cloud forest at elevations above 2,200 m. It has been encountered as a common but patchily distributed species — present with enough regularity to be part of the local orchid community, but clustered rather than uniformly dispersed through suitable habitat. The occurrence at La Honda is consistent with the broad "frequent at high altitudes through the Andes" characterisation of the species by Luer & Thoerle (2012).

Lepanthes tachirensis is a Northern Andean species, not a Colombian endemic — the first such species documented in this book. It is known from Venezuela (type locality: Táchira, at the locality where J. A. Steyermark, G. C. K. & E. Dunsterville 98524 was collected as the holotype, deposited at VEN), Colombia (Antioquia, Norte de Santander, Chocó, Quindío, Nariño), and Ecuador (Carchi, Imbabura, Pichincha, Morona-Santiago, Loja, Tungurahua, Zamora-Chinchipe), spanning all three Colombian cordilleras and the continuous Andean range from ~8° N in Venezuela to ~4° S in southernmost Ecuador (Foldats, 1968; Luer & Thoerle, 2012; POWO, 2026).

The La Honda record documents the species in the Cordillera Central of Antioquia on the eastern slope — a new-locality addition that falls well within the published distribution.

Flowering has been observed in La Honda. The available data do not yet support a reliable characterisation of the local phenology; systematic observation across a full annual cycle would be required. No flowering-season data have been published for this species in its broader range.

Recognition rests on the combination of the tall, pale-tan-sheathed ramicauls (sheaths glabrous with non-dilated ostia, distinguishing the species from many congeners with ciliate, funnel-mouthed sheaths), the narrowly ovate-elliptical coriaceous leaf, the slender peduncle borne behind the leaf, and the diagnostic petal architecture: orange petals with purple margin, transversely bilobed, bearing a prominent fingerlike lobule on the inner apical angle of each upper lobe that overlaps with the lobule of the paired petal. This petal lobule is the single most distinctive external character of the species and is visible in well-posed field photographs. The lateral sepals diverge 180° — a wider spread than in the superficially similar Lepanthes speciosa of northwestern Ecuador, which has laterals diverging only ~90° and a subcircular, concave upper petal lobe (Luer & Thoerle, 2012).

Lepanthes tachirensis 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. In contrast to the narrow-range Colombian endemics described elsewhere in this chapter, L. tachirensis is documented from a wide range across three countries and all three Colombian cordilleras, and Luer & Thoerle (2012) characterise it as "frequent" throughout this range. The species is therefore likely not globally threatened. However, like all miniature Lepanthes, individual microsites remain vulnerable to specialist collection, and the species' long-term persistence at any single locality depends on the continuity of mid-to-high-elevation cloud forest habitat.

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. tachirensis has been documented is not published, and precise 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].