Pyxine boonpragobiana Kalb & Mongkolsuk, 2012

Mongkolsuk, Pachara, Meesim, Sanya, Poengsungnoen, Vasun & Kalb, Klaus, 2012, The lichen family Physciaceae in Thailand-I. The genus Pyxine, Phytotaxa 59 (1), pp. 32-54 : 38-39

3. Pyxine boonpragobiana Kalb & Mongkolsuk , sp. nov. ( Fig. 3A )

Mycobank MB 800692

Similar to Pyxine fallax (Zahlbr.) Kalb (showing the same terpene profile on TLC plates in solvent A, B' and C), but differing in having polysidiangia.

Holotype:— THAILAND. Loei; Phu Luang Wildlife Sanctuary, Khok Huai Toei , in a lower montane rainforest, on an unidentified tree, 1240 m, 17°19'46'' N, 101°31'26'' E, 25 August 2008, S. Meesim MS78 ( RAMK 17622 ).

Thallus corticolous, 3–5 cm wide, loosely to tightly adnate. Lobes radiating, discrete to contiguous or imbricate, plane to weakly concave, 0.5–1.0 mm wide, subrotund to truncate at the apices. Upper surface pale to lead grey, with a weak punctiform pruina towards the lobe tips or epruinose; true isidia and soralia absent. Pseudocyphellae present but not conspicuous, laminal, becoming ± reticulate. Polysidiangia robust, mainly marginal, occasionally laminal, scattered or clustered, nodular to subcylindrical or clavate, short, ± branched, pustulate, bursting apically to release corticate fragments, soredia absent. Medulla uniformly white. Lower surface black in the centre, paler towards the margin; rhizines ± dense, simple or irregularly branched. Apothecia rare (not present in holotype), obscurascens -type, 1–2 mm wide, disc epruinose. Internal stipe distinct, orange in upper part, K+ purple, C-, KC-, P+ dark purple, white in lower part, K+ deep orange, P-, C-, KC-. Pycnidia not seen.

Chemistry: Cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K+ yellow → red, C-, P+ orange; containing atranorin (major), chloroatranorin (minor), norstictic acid (major), testacein (submajor), unknown terpenes showing the same profile as P. fallax and P. profallax (minor).

Distribution and habitat:—A rare species, on bark in humid dipterocarp forests, lower montane scrubs and lower montane rainforests at 1240–1660 m elevation. So far only known from Thailand.

Notes:— Pyxine boonpragobiana is characterized by the marginal polysidiangia, cortical atranorin, the white medulla, the presence of medullary norstictic acid, testacein and a characteristic array of terpenes. It is morphologically similar to P. coralligera and P. subcoralligera , but both differ in containing a different suite of terpenes and lack norstictic acid as a medullary substance. P. profallax and P. fallax show the same terpene profile as P. boonpragobiana , but P. profallax lacks vegetative propagules and P. fallax has elevated, laminal soralia. Morphologically also similar is P. retirugella , but this species differs by a different suite of terpenes.

Etymology: —The new species is named in honour of Associate Prof. Dr. Kansri Boonpragob, head of the Lichen Research Unit at Ramkhamhaeng University, Bangkok, esteemed Thai lichenologist and an ever helpful friend.

Material from Thailand examined:— Chiang Mai; Queen Sirikit Botanic Garden , on Syzygium claviflora in an open, dry dipterocarp forest, 730 m, 18°53'54'' N, 98°51'38'' E, 1 July 1994, K . Boonpragob 3934 ( RAMK 17625 ).— Chiang Mai; Lumphun, Mae On , descent from Doi Mon Larn to Mae Kam Pong village , on bark in an evergreen mountain forest, 1500 m, 18°51' 22'' N, 99°22'02'' E, 19 March 2008, K . Kalb (hb. Kalb 36912).— Chiang Mai; Doi Suthep-Pui National Park , Peak of Doi Suthep-Pui , in an open humid dipterocarp forest, 1660 m, 18°50'03'' N, 98°53'16'' E, 17 March 2008, K . Kalb (hb. Kalb 36928).— Loei; Phu Luang Wildlife Sanctuary , in front of seven channel television station at Khok Nok Kraba Forest Ranger Station , in a lower montane scrub on an unidentified tree, 1250 m, 17°16'53'' N, 101°31'22'' E, 25 March 2009, S . Meesim MS6 , ( RAMK 17621 ) .

Figures

FIGURE 3. A. Pyxine boonpragobiana (hb. K. Kalb 36928), thallus with polysidiangia; Scale: 3 mm. B. Pyxine dactyloschmidtii (holotype), thallus with polysidiangia; Scale: 3 mm. C. Pyxine pseudoceralensis (holotype), thallus with isidia; Scale 2 mm. D. Pyxine subcoralligera (holotype), thallus with polysidiangia; Scale 3 mm. E. Pyxine cylindrica (hb. K. Kalb 36836), thallus with marginal and partly laminal isidia; Scale 2 mm. F. Pyxine cognata (hb. K. Kalb 12344), thallus with obscurascens-type apothecia and patchy priuna; Scale 3 mm.