Phaeoceros kashyapii A. K. Asthana & S. C. Srivast., Bryophyt. Biblioth.

Phaeoceros kashyapii A. K. Asthana & S. C. Srivast., Bryophyt. Biblioth. View in CoL 42: 129, pl. 30, 48. 1991.

Figs 6 View Figure 6 , 7 View Figure 7 , 11 A, B View Figure 11

Type.

India • Western Himalayas: Deoban. 29 Sep 1976, D. K. Singh & J. C. J. 2170 / 76 ( holotype: LWU!) .

Description.

Thallus bright green to yellowish green in fresh samples, become yellowish green to dark brown when dry, growing prostrate with moderately adhering to substrate, forming irregular patches or fan-shaped colonies, irregularly branched into several lobes, thallus lobe lingulate to obovate, or fan-shaped, the base usually narrower than the apex, 7–20 mm long, 2–6 mm wide; margins nearly entire to irregularly crenulate, sometimes lobulate along the margin, flat, rarely ascending upward; apex generally lobulate, broad, occasionally attenuate into apical tuber, rarely curving upward; tubers frequently present, occurring at apex, along margin, or on ventral surface of thallus, with a stalk to 5 mm long, ovoid to subspherical. Thallus in cross section plano-convex to concave-convex, 4–8 cells thick in the middle region. Dorsal epidermal cells irregular pentagonal to heptagonal, 30–150 × 20–55 µm. Chloroplasts 1 per cell, expanded, occupying nearly entire to half of cell size, frequently contracted into round shape, pyrenoid smooth. Nostoc colonies scattered ventrally, appearing as dark spots. Rhizoids sparse, scattered mainly along the middle region of ventral surface, smooth in early stage, becomes pegged at maturity, hyaline to pale brown. Sexuality monoicous or strong protandrous, androecia and archegonia not seen. Involucres erect, conical-cylindrical, 1.2–1.7 mm long, 2–4 cells thick, mouth smooth to shallowly crenulate. Sporophytes frequent, capsules erect, cylindrical, up to 15 mm long at maturity; epidermal cells of capsule elongate-rectangular, 117–300 × 10–28 µm; stomata 70–83 × 42–85 µm, surrounded by 5–6 epidermal cells; assimilative layer 2–4 cells thick in cross section; the innermost capsule cells elongate rectangular to hexagonal, 37–155 × 7–28 µm, pale brown to brown; columella consisting of 4–8 cells in cross section, brown to dark brown. Spores yellowish brown to dark brown, 30–38 µm in equatorial diameter; distal face with irregular large verrucose confined to the center; proximal face with distinct thin triradiate mark, finely vermiculate along its length; each facet finely vermiculate, frequently with sparse papillae confined to the center of each facet. Pseudoelaters thin to thick-walled, occasionally branched, 1–3 cells long; pseudoelaters cells irregular rectangular, yellowish brown to dark brown, without helicoidal band.

Distribution, habitat, and ecology.

Phaeoceros kashyapii usually grows in open areas in pine-oak forests ranging from 900–2,200 m in elevation.

Distribution.

India and Thailand ( Asthana and Srivastava 1991).

Conservation status.

Phaeocero kashyapii has an estimated EOO of 200,894 km 2, suggesting a status of Least Concern ( LC), while its area of occupancy ( AOO) is 36 km 2, which would place it in Endangered ( EN). Indian populations are more widely distributed and can be found in disturbed areas, while Thai populations are rare and found alongside walking trails in the conservation areas. However, it is unclear whether the species continued occurrence at some of these sites. Its habitats are probably impacted by development and human disturbance. Therefore, P. kashyapii could be qualified as Endangered ( EN) according to the IUCN Red List Criteria B 2 ab (iii) ( IUCN 2024).

Specimens examined.

India • Uttarakhand: Mussoorie, Dehra Dun, Wood Stock College , 2,121 m elev., 3 Oct 1977, S. Chandra 203383 ( LWG); Nainital, on the way to Kilbury, ca 1,818 m elev., 12 Sep 2001, A. P. Singh & V. Sahu 208947 ( LWG) ; • Nainital, on the way to Tippin top, ca 2,181 m elev., 13 Sep 2001, A. P. Singh & V. Sahu 208975 A ( LWG) ; • Uttarkashi, Silkiara , 1,818 m elev., 15 Sep 1977, S. Chandra 203222, 203225 B, 203225 C ( LWG) ; • Syana Chatti, Janki Chatti , 1,818 m elev., 20 Sep 1977, S. Chandra 203253 A ( LWG) ; • Western Himalayas: Deoban , 29 Sep 1976, D. K. Singh & J. C. Joshi 2170 / 76 ( LWU) . Thailand • Chiang Mai: Chiang Dao, Doi Sam Phe Nong , ca 1,500 m elev., 10 Oct 2019, S. Chantanaorrapint & O. Suwanmala 3898, 3900, 3901 ( PSU) ; • Pang Woa , 19 ° 24 ' 33.05 " N, 098 ° 51 ' 35.46 " E, 1,178 m elev., 13 Nov 2016, S. Chantanaorrapint & O. Suwanmala 718 A ( PSU) GoogleMaps ; • Lum Phun: Khun Tan National Park , 18 ° 29 ' 55.34 " N, 099 ° 16 ' 43.92 " E, 904 m elev., 11 Oct 2019, S. Chantanaorrapint & O. Suwanmala 3920 ( PSU) GoogleMaps .

Taxonomic notes.

Phaeoceros kashyapii is similar to P. himalayensis in several morphological characters of the gametophyte and sporophyte. Both are monoicous and usually grow in irregular patches. The thallus frequently produces tubers with long stalks on the ventral side, margins, and apex. Sporophytes are no longer than 15 mm, turning yellowish brown at maturity with an adhering valve tip. However, P. kashyapii differs from P. himalayensis by its spores lacking a central hollow on the proximal facet and usually bearing a small cluster of minute papillae restricted to the central region of each facet.

The examination of the holotype of P. kashyapii revealed that the spores of the type collection have a depression at the center of each facet, which morphologically resembles P. himalayensis . This indicates that the holotype of P. kashyapii is possibly mixed. The original publication of P. kashyapii also noted that it was found associated with P. himalayensis . Nevertheless, all specimens examined in this study display characteristics that belong to P. kashyapii , based on the first description and photographs provided by Asthana and Srivastava (1991). Based on collections from Thailand, gametophytes are strongly protandrous, with antheridia or antheridial chambers rarely found in sporophyte-bearing thalli. However, it is quite clear that the Indian population of P. kashyapii presents a monoicous plant producing male and female gametes on the same thallus.

The proximal spore architecture of P. kashyapii is typically finely vermiculate, with sparse minute papillae limited to the center of each facet. However, the papillae may be present in small numbers or occasionally absent. In such cases, it is quite difficult to distinguish spores of P. himalayensis and P. kashyapii using a light microscope. Therefore, careful investigation of the proximal face of the spore is required for accurate species recognition.