Lepanthes heteroloba is a small, epiphytic, caespitose orchid with slender roots. The ramicauls are slender and erect, more or less arching near the leaf, 5–7 cm long, enclosed by 7–8 microscopically ciliate, close, lepanthiform sheaths with acuminate tips. The single leaf is horizontal to pendent, coriaceous, ovate, acute and acuminate at the tip, rounded at the base, 3–3.5 cm long and 1.2–1.3 cm wide; the base is contracted into a petiole less than 1 mm long.

The inflorescence is a very congested, successively many-flowered raceme up to 9 mm long, borne on top of the leaf by a filiform peduncle 2–8 mm long; floral bracts 0.75 mm long; pedicels overlapping, 1.5 mm long; ovary 1.5 mm long. The sepals are glabrous, translucent light yellow and suffused with light purple at the base. The dorsal sepal is ovate, subacute, 5.4 mm long and 2.2 mm wide, 3-veined, fused to the lateral sepals for 0.5 mm. The lateral sepals are ovate, oblique, subacute to obtuse and minutely denticulate, each 2.75 mm long and 1.5 mm wide, 2-veined, fused for 1.5 mm.

The petals — the diagnostic feature — are orange, microscopically cellular, transversely bilobed, 0.5 mm long at the base and 3.5 mm wide, with a capillary marginal lobule 1 mm long emerging between the lobes. The upper lobe is obliquely oblong, subtruncate, 2.5 mm long and 1.3 mm wide, 2-veined; the lower lobe is triangular, sharply acute, 1 mm long and 0.5 mm wide — markedly smaller than the upper. The lip is translucent red, bilaminate, with the blades semi-oblong with rounded ends, adherent to each other over the column, 1.25 mm long; the connectives are narrow, oblique and inserted above the middle of the blade; the body is short, fused to the base of the column; the sinus is obtuse with an oblong, pubescent appendix, transversely cleft at the tip, 0.4 mm long. The column is 2 mm long, with the anther dorsal and the stigma ventral.

The morphological characters described here follow Luer, Escobar & Thoerle (2011), with the same characters reproduced in Luer & Thoerle (2012) in Icones Pleurothallidinarum XXXII the following year.

The published literature describes Lepanthes heteroloba as an epiphyte of montane forest in the Cordillera Central of Antioquia. The protologue (Luer, Escobar & Thoerle, 2011) cites the holotype from cloud forest at Mesopotamia at 2,400 m elevation. Luer's discussion characterises the species as "delicate" with "drooping leaves and a very congested raceme atop," and notes that L. heteroloba is sympatric with L. quandi — a species not yet documented at La Honda but published from the same general region.

In La Honda, L. heteroloba has been observed between approximately 1,900 and 2,500 m as an epiphyte on twigs, branches and trunks of mature montane forest. The species is the most readily detected Lepanthes in the project: where most members of the genus at the site require careful search-image work — small ramicauls hidden in moss, miniature flowers easily overlooked — L. heteroloba is encountered repeatedly and recognised at first glance, both because the flower is comparatively large for the genus (sepals to 5.4 mm) and because the colouration — translucent yellow sepals and a magenta column-and-lip set against orange petals — reads vividly against the green leaf background.

Lepanthes heteroloba is endemic to Colombia and known from the Cordillera Central of Antioquia (POWO, 2026; Luer, Escobar & Thoerle, 2011; Luer & Thoerle, 2012; Idárraga-Piedrahita et al., 2011).

The protologue (Luer, Escobar & Thoerle, 2011) cites the holotype from Mesopotamia, Antioquia, at 2,400 m — collected by R. Escobar (no. 3421) on 25 May 1984, with the holotype deposited at MO and an illustration by C. Luer (illustr. 11391). The 27-year gap between collection (1984) and formal description (2011) reflects the gradual pace at which Luer and his collaborators worked through the Antioquian Lepanthes backlog at the Sociedad Colombiana de Orquideología — a pattern visible across many of the species in this book.

The Mesopotamia type locality places L. heteroloba alongside L. cactoura and L. auditor as the third species in this book whose type locality is the municipality of Mesopotamia — an emerging editorial thread that reflects both the richness of the Mesopotamian Cordillera Central forests as a Lepanthes diversity centre and the sustained collecting effort of the Luer–Escobar partnership in that area through the 1980s and beyond.

The La Honda record at 1,900–2,500 m sits within the documented elevational range and within the broader eastern-Antioquian Cordillera Central corridor that connects Mesopotamia and the surrounding municipalities.

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 very congested, successively many-flowered raceme architecture noted in the protologue means that fertile plants commonly bear several flowers in different states of development simultaneously, alongside ripening capsules.

Lepanthes heteroloba is the easiest Lepanthes to recognise in the field at La Honda, distinguished by a combination of vegetative habit and floral architecture that yields an immediately distinctive search image.

Vegetatively, look for slender erect ramicauls 5–7 cm tall — taller and more substantial than most miniature Lepanthes at the site — bearing a single ovate, acuminate leaf 3–3.5 cm long that droops horizontally or pendently rather than standing erect. The very congested raceme of flowers sits on top of the leaf on a short filiform peduncle, often visible as a small clustered structure perched at the leaf's centre line.

Florally, the diagnostic features are: (i) translucent yellow sepals, the dorsal broadly ovate-subacute and the laterals ovate-oblique with distinctively minutely denticulate margins; (ii) bilobed orange petals with strongly asymmetric lobes — an obliquely oblong, much-larger upper lobe contrasting with a sharply acute, much smaller, triangular lower lobe — and a slender capillary midlobe emerging from the petal margin between the two lobes (the namesake "different lobes" character); (iii) a translucent red, bilaminate lip with semi-oblong blades adherent over the column.

Luer's protologue diagnosis flags L. heteroloba as superficially similar to L. quandi and notes its kinship with the L. mucronata complex — relatives also linked to L. mucronata (already in the book) and to L. debilis, which shares the membranous lip-blade character. L. heteroloba differs from L. quandi in having subacute (not shortly acuminate) sepals, and from both L. quandi and the mucronata allies in its strongly asymmetric petal lobes and the diagnostic capillary midlobe.

Lepanthes heteroloba 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. heteroloba is a narrow Antioquian endemic, currently known from only a small number of localities in the Cordillera Central. The species's apparent local abundance at La Honda — visible and easily recorded — should not be misread as a signal of broader range-scale security: an endemic that is locally common at one site can still be vulnerable at the regional scale if its small documented range is exposed to forest loss and microclimate change, both of which are operative in eastern Antioquia. Locally, persistence depends on the continuity of mature montane forest and intact moss-bearing twig, branch and trunk substrates within the species's elevational band.

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. heteroloba has been documented is not published, and precise elevation data beyond the approximate 1,900–2,500 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].