Platygramme commutabilis ( Krempelhuber 1875: 33 ) A. W. Archer (2009: 652)

Kalb, Jutarat & Kalb, Klaus, 2017, New lichen species from Thailand, new combinations and new additions to the Thai lichen biota, Phytotaxa 332 (2), pp. 141-156 : 149

Platygramme commutabilis ( Krempelhuber 1875: 33) A. W. Archer (2009: 652) . ( Fig. 2F )

Three species with 1-spored asci are known to occur in Thailand, viz. P. platyloma , P. pudica and P. commutabilis (ascospores 70–110 × 17–29 μm). The latter is easily separated from the first two species in having much smaller ascospores (125–180 × 30–40 μm in P. platyloma and 160–200 × 30–40 μm long in P. pudica ). Furthermore, P. commutabilis and P. platyloma lack secondary products, while P. pudica contains echinocarpic acid.

Distribution and habitat:—Known from Malaysia and Australia and here reported from Thailand for the first time. It was found growing on bark of various trees ( Durio zibethinus , Hopea odorata , Parkia speciosa , Azadirachta excelsa , Hevea brasiliensis and Alstonia macrophlla ).

Selected material from Thailand examined (65 specimens collected):— Chumphon province: Pathio district, tambon Chum Cho, forest on the right hand side of the road, about 600 m from tri-section to Bangson Bay, on bark of unidentified tree, 25 m; 10°26’31” N, 99°26’46” E, 14 April 2009, J. Sutjaritturakan 2004 (Hb. K. & J. Kalb), conservative forest in the area of King Mongkut’s Institut of Technology Ladkrabang, Prince of Chumphon campus, on bark of unidentified tree, 10 m; 10°26’23” N, 99°13’03” E, 8 April 2009, J. Sutjaritturakan 2195 (Hb. K. & J. Kalb); Lang Suan district, tambon Tha Maphla, Rad Buranaram Temple, on trunk of Durio zibethinus , 20 m, 09°56’24” N, 99°02’26” E, 16 May 2009, J. Sutjaritturakan 2627, 2629, 2635, 2645 & 2646 (Hb. K. & J. Kalb).— Trang province: Hat Samran district, tambon Hat Samran Moo 6, on Hopea odorata , 10 m; 07°12’28” N, 99°36’00” E, 26 May 2009, J. Sutjaritturakan 2859 (Hb. K. & J. Kalb); Palian district, in the area of tambon Suso Moo 1, on Parkia speciosa , 25 m, 07°15’29” N, 99°40’44” E, 22 May 2009, J. Sutjaritturakan 2877 & 2881 (Hb. K. & J. Kalb); on Azadirachta excelsa , 25 m, 07°15’29” N, 99°40’44” E, 22 May 2009, J. Sutjaritturakan 2904 & 2907 (Hb. K. & J. Kalb); on Hevea brasiliensis , 25 m, 07°15’29” N, 99°40’44” E, 22 May 2009, J. Sutjaritturakan 2924, 2947 & 2956 (Hb. K. & J. Kalb).— Phuket province: Thalang district, tambon Thep Krasattri, in the area of Ban Kokwatmai, on Hevea brasiliensis , 25 m, 08°01’57”, 98°20’40” E, 17 April 2012, J. Sutjaritturakan 3963 (Hb. K. & J. Kalb).—Phang-Nga province: Mueang district, tambon Tak Daet, in the area of Ban Suanprik, on Hevea brasiliensis , 35 m, 08°28’05”N, 98°28’58” E, 26 April 2012, J. Sutjaritturakan 4216 & 4235 (Hb. K. & J. Kalb); on bark of unidentified trees, 35 m, 08°28’05”N, 98°28’58” E, 26 April 2012, J. Sutjaritturakan 4225 (Hb. K. & J. Kalb 42227).—Patthalung province: Srinakarindra district, in the area of Ton Phrae Thong Waterfall, on trunk of unidentified tree, 75 m, 08°28’05”N, 98°28’58” E, 28 May 2012, J. Sutjaritturakan 4617 (Hb. K. & J. Kalb); Srinakarindra district, in the area of Ton Phrae Thong Waterfall waterfall, on trunk of Alstonia macrophylla , 75 m, 07°29’13” N, 98°28’58” E, 28 May 2012, J. Sutjaritturakan & S. Siemmai 4641 (Hb. K. & J. Kalb).— Nakhon Si Thammarat province: Thung Yai district, Ban Kuanlumpoo, on Hevea brasiliensis , 45 m, 08°28’05”N, 98°28’58” E, 26 April 2012, J. Sutjaritturakan 4903 (Hb. K. & J. Kalb).

Remarks:—In the protologue, the spore size is given as 80–110 × 25–33 μm ( Krempelhuber 1875). Although we have measured many spores from numerous specimens all almost identical to the lectotype, we only rarely have found spores broader than 25 and longer than 95 μm. It is difficult to understand why this species has not been reported for Thailand before, because it is by far the most common species of Platygramme and no less than 65 specimens were collected in the course of this study.

Figures

FIGURE 2. A. Graphis indica (J.K. & K.K, KJK 41769; scale 1 mm); B. Leucodecton occultum (J.K. & K.K, KJK 41952; scale 0.25 mm); C. Phaeographopsis palaeotropica, ascomata with a distinct black mazaedium (J.K. & K.K, KJK 41398; scale 0.5 mm); D. Phaeographopsis palaeotropica, ascomata lacking a mazaedium (J.K. & K.K, KJK 41395; scale 0.4 mm); E. Platygramme australis (J.K. & K.K, KJK 41279; scale 0.5 mm); F. Platygramme commutabilis (Sutjaritturakan 4225, KJK 42227; scale 1 mm); G. Platygramme discurrens (Sutjaritturakan 4895, KJK 42217; scale 0.3 mm); H. Platygramme subcolubrosa (J.S. & K.K., KK 41534; scale 0.5 mm).