Lepraria malakandensis H. Wahab, Sirajuddin & Khalid

Wahab, Hira, Wahab, Afshan, Anwar, Ayesha, Uddin, Siraj, Ahmad, Shabir, Iqbal, Rashid & Khalid, Abdul Nasir, 2025, A new species of the lichen genus Lepraria (Lecanorales: Stereocaulaceae) from Pakistan, Phytotaxa 708 (2), pp. 197-207 : 201-203

Lepraria malakandensis H. Wahab, Sirajuddin & Khalid

MycoBank No.: MB836656

Etymology:— The specific epithet malakandensis refers to the type locality, Malakand, KP, Pakistan.

Habitat: found at an elevation of above 1107 m.a.s.l., in partially forested area on soil, partially exposed to sun, along road side, mean max. and min. temperature: 30°C and 4°C, respectively, climate is warm and temperate. It is a biologically, geo-physically, and hydrologically dynamic area.

Holotype:— PAKISTAN. Khyber Pakhtunkhwa Province: Malakand division, District Malakand, Agra ; 34°34′35.19″ N, 71°41′21.92″ E, 1107 m; December 17, 2016, Hira Wahab, Bot-20164 ( MT802114 , holotype).

Diagnosis:— Similar to Lepraria vouauxii , but distinguished by the presence of aggregated, soredia-like granules and a whitish-grey to greenish-grey thallus. This species produces atranorin, zeorin, stictic acid, and constictic acid as its major secondary metabolites, whereas L. vouauxii contains pannaric acid-6-methylester.

Additional material examined:— PAKISTAN. Khyber Pakhtunkhwa Province: District Malakand, Totakan ; 34°30′11.43″ N, 71°54′16.60″ E, 626 m; December 17, 2016, Hira Wahab Bot-20165 ( MT802113 , Isotype)

Description

The thallus is crustose and leprose, lacking lobes, and typically patchy but becoming more continuous with maturity. It consists of soredia-like granules, giving it a powdery to granular texture. The thallus color varies from whitish gray to greenish gray, with a thickness of approximately 0.7 mm. The prothallus is present in early growth stages but becomes excluded or inconspicuous with age; it is black, providing a distinct contrast to the thallus. The hypothallus is rarely observed but, when present, is also black. Rhizohyphae are dark green, approximately 2 μm wide, and infrequently seen. The granules are globose, ranging from 20–40 μm in diameter. The photobiont is a green, coccoid alga with globose cells measuring 7–13 μm in diameter. Chemistry: Thallus contains K+ yellow, C–, KC– and PD+ orange; atranorin, zeorin, stictic acid and constictic acid detected in TLC.

Ecology: The species has been found growing on Calcareous rock in a temperate climate at an altitude of 1107 m a.s.l., moist and sun exposed habitats, having surrounding trees of Acacia modesta L., Dodonae aviscosa (L.) Jacq. Cedrus deodara (Roxb. ex D. Don) G. Don. , Pinus wallichiana A.B.Jackson. , Punica granatum L., Quercus dilatata Royle. , Quercus incana Roxb. and Selaginella jacquemontii Spring.

Notes. The newly described species distinguished from Lepraria vouauxii by its aggregate, soredia-like granules and a whitish gray to greenish gray thallus. While L. vouauxii produces pannaric acid 6-methyl ester and related compounds, the new species differs chemically by producing atranorin, zeorin, stictic acid, and constictic acid as its major secondary metabolites. These differences in thallus structure and chemistry suggest that the new species represents a distinct taxon within Lepraria (Lendemer & Hodkinson, 2013) . The only other Lepraria species previously recorded from Pakistan, L. membranacea , produces pannaric acid, roccellic/angardianic acid, and occasionally atranorin ( Kukwa, 2019).

Lepraria finkii shares some chemical similarities with L. malakandensis , but also contains trace amounts of cryptostictic, norstictic, and peristictic acid. It differs morphologically, having a greenish gray to bluish green thallus with fluffy soredia ( Rambaut, 2014). Another species, Lepraria cryophila Lendemer , differs both in morphology and chemistry, featuring an off-white to light blue-white thallus, a visible hypothallus, and the divaricatic acid chemosyndrome ( Table 1), often with traces of atranorin (Rizwana et al. 2020).

Although L. malakandensis and L. elobata share the same secondary metabolites, they can be distinguished by morphological traits. L. malakandensis has a whitish-grey to greenish-grey thallus, whereas L. elobata exhibits a diffuse, pale blue-grey to dull blue-grey thallus ( Table 1). While their granule size ranges overlap ( L. malakandensis : 20–40 µm; L. elobata : 30–120 µm), L. elobata tends to have a wider variation with larger granules.These morphological differences, in combination with phylogenetic evidence, support the recognition of L. malakandensis as a distinct species.

Lepraria malakandensis is distinct from L. lobificans in both morphology and chemistry. L. malakandensis has a crustose, leprose thallus with a powdery to granular texture, whereas L. lobificans tends to form a more structured leprose to placodioid thallus. The former is whitish-gray to greenish-gray, whereas L. lobificans often appears bright green or greenish-gray. Additionally, L. malakandensis possesses a black prothallus in its early stages, which is absent in L. lobificans . Chemically, L. malakandensis lacks atranorin, angardianic/roccellic acid, and protocetraric acid, which are characteristic of L. lobificans (Rizwana et al. 2020) .

Lepraria malakandensis and L. neglecta (Nyl.) Erichsen share morphological and chemical similarities but can be distinguished based on granule size, secondary metabolite profiles, and phylogenetic placement. L. neglecta typically has larger granules (30–[42]–59–[77]–[102] µm) compared to L. malakandensis (20–40 μm). While L. malakandensis contains atranorin, zeorin, stictic acid, and constictic acid, L. neglecta generally produces alectorialic and angardianic acids, with only trace amounts of atranorin. However, the L. neglecta group is known to exhibit extensive chemical variation across different populations and geographic regions (Guzow-Krzemińska et al. 2019; Lendemer 2013; Saag et al. 2007). Given this variability, chemical differences alone may not be sufficient for species delimitation. Instead, the distinction of L. malakandensis is further supported by its phylogenetic separation from L. neglecta , as previously demonstrated (Timdal & Tønsberg, 2002).

Lepraria malakandensis and L. ulrikii Grewe , Barcenas-Pẽna, Diaz & Lumbsch share morphological and chemical similarities but differ in thallus structure. L. ulrikii has a placodioid, finkii-type thallus with a greenish coloration, whereas L. malakandensis has a leprose, whitish-gray to greenish-gray thallus. Additionally, L. malakandensis features a distinct black prothallus in early stages, while L. ulrikii exhibits a different marginal development. Despite these similarities, phylogenetic analysis confirm that they represent separate evolutionary lineages ( Barcenas-Peña, 2021).

The discovery and extensive research of Lepraria malakandensis contribute significantly to our understanding of Lepraria diversity, particularly in Pakistan. Our study, which is based on significant morpho-anatomical, chemical, and phylogenetic evidence, emphasizes the distinctiveness of L. malakandensis , particularly when compared to closely related species such as L. cryophila . This study emphasizes the value of DNA data in distinguishing cryptic species within the Lepraria genus, providing clarity where morphological and chemical markers alone may be insufficient. The identification of L. malakandensis not only contributes to the global taxonomy of lichenized fungi but also enriches our understanding of Pakistan’s lichen biodiversity.