[ticolichen-Logo] provisional
determination keys
for the Graphidales
of Costa Rica
[bgbm-Logo] [graphidales-Logo] by H. Sipman
BGBM
last updated:
18 August 2008
other webkeys
other Zschackia issues
intro - genera - Acanthothecis - Anomomorpha - Aulacographa - Carbacanthographis - Diorygma - Dyplolabia - Fissurina - Glyphis - Graphis - Hemithecium - Leiorreuma - Phaeographis - Phaeographopsis - Platygramme - Platythecium - Sarcographa - Thalloloma - Thecaria -
corticolous Thelotremataceae

The species of Diorygma in Costa Rica

1A Thallus UV+ orange, with lichexanthone; ascocarps very irregularly widened, often with exposed disc - - - 2
1B Thallus UV- (rarely UV+ yellow), without lichexanthone; ascocarps more uniform, mostly lirelline, closed or with exposed disc - - - 3

2A Ascospores over 135 mu long, central cells enlarged - - - Diorygma epiglaucum
2B Ascospores under 135 mu long, central cells not enlarged - - - Diorygma confluens

3A Ascocarps with linear, almost closed discs; ascospores 2-8/ascus - - - 4
3B Ascocarps with wider and distinctly exposed discs; ascospores 1/ascus - - - 6

4A Ascospores I-; cells irregularly arranged - - - Diorygma sipmanii
4B Ascospores I+ violet; cells in transverse layers - - - 5

5A Ascospores over 70 mu long; ascocarps often bordered by swollen, margin-like thallus - - - Diorygma intermedium
5B Ascospores under 70 mu long; ascocarps mostly without swollen thallus border - - - Diorygma poitaei

6A Thallus easily flaking off from the substrate, with black lower side; with norstictic and salazinic acids; on underside of canopy branches - - - Diorygma salvadoriense
6B Thallus firmly attached to substrate, without black lower side; with norstictic, salazinic, protocetraric acids alone or in combinations; on trunks and upper side of branches - - - 7

7A Thallus K+ yellow turning orange, with norstictic or stictic acid - - - 8
7B Thallus K- or K+ pale brownish, with protocetraric acid - - - Diorygma pruinosum

8A Thallus with norstictic acid as major substance, with or without salazinic acid - - - 9
8B Thallus with stictic acid as major substance, without salazinic acid - - - Diorygma hieroglyphicum

9A Thallus with norstictic acid alone - - - Diorygma junghuhnii
9B Thallus with norstictic and salazinic acids as major substances - - - Diorygma reniforme

REFERENCE: Kalb, K., Staiger, B. & Elix, J.A. 2004. A monograph of the lichen genus Diorygma - a first attempt. Symb. Bot. Ups. 34(1): 133-181.

Diorygma confluens (Fe) Kalb, Staiger & Elix (Graphina confluens (Fe) Mll. Arg.) - Ascocarps elongate or rounded, immersed, sometimes surrounded by swollen thallus border; hymenium 100-160 mu, clear, I+ pale blue; ascospores 1/ascus, muriform, I- or I+ violet, ca. 100-130 x 30-50 mu. Major substances: lichexanthone, stictic, constictic acids. Specimens studied: Sipman 51606, 51049c, 12037 (as "Graphina collatinensis").
[D. confluens]
Costa Rica (Sipman 51049c); picture length = 7 mm.

Diorygma epiglaucum (Mll. Arg.) Kalb, Staiger & Elix (Kalb et al. 2004) - Ascocarps elongate or rounded, immersed, sometimes surrounded by swollen thallus border; hymenium ca. 180 mu, clear, I- or I+ pale blue; ascospores 1/ascus, muriform, I- or I+ violet, ca. 140-175 x 50 mu. Major substances: lichexanthone, stictic, constictic acids. Specimens studied: Sipman 51657, 51668, 53224, 53381.
[D. epiglaucum] [D. epiglaucum]
Costa Rica (Sipman 51668); picture length = 7 mm. Costa Rica (Sipman 53224); picture length = 7 mm.

Diorygma hieroglyphicum (Pers.) Staiger & Kalb - Ascocarps variously shaped, often stellar with rather narrow discs and immersed, sometimes less branched and surrounded by swollen thallus border; hymenium ca. 100 mu, clear, I+ blue; ascospores 1/ascus, muriform, ca. 90 x 40 mu. Major substance: stictic acid. Specimen studied: Sipman 12321 (as "Graphina collatinensis"), 53404.
[D. hieroglyphicum] [D. hieroglyphicum]
Papua New Guinea (Sipman 24312); picture length = 7 mm. Costa Rica (Sipman 53404); picture length = 7 mm.

Diorygma intermedium Kalb, Staiger & Elix - Ascocarps linear, immersed, sometimes surrounded by swollen thallus border; hymenium ca. 200-220 mu, clear, partly I+ blue; ascospores 8/ascus, muriform, I+ dark violet, ca. 180-100 x 16-20 mu. Major substance: hypostictic acid. Specimens studied: Sipman 51878, 51796, Aptroot 60720, 60578. Note: D. intermedium is very similar to D. poitaei and differentiated by its spore size. It is tentatively assumed here that the frequent specimens without spores and without swollen thallus borders along the ascocarps belong to D. poitaei. Specimen Aptroot 60578 shows a strong, yellow fluorescens, particularly in the ascocarps, but by TLC no additional substance was found.
[D. intermedium] [D. intermedium]
Costa Rica (Sipman 51796); picture length = 7 mm. El Salvador (Sipman 37862); picture length = 7 mm.
[D. intermedium]
Costa Rica (Aptroot 60720), ascospores stained with iodine; picture length = 310 mu.

Diorygma junghuhnii (Mont. & v.d. Bosch) Kalb, Staiger & Elix (Graphina mendax (Nyl.) Mll. Arg.) - Ascocarps variously shaped, with exposed disc, immersed, surrounded by swollen thallus border; hymenium 100-130 mu, clear, I+ blue; ascospores 1(-2)/ascus, muriform, ca. 80-125 x 20-40 mu. Major substance: norstictic acid. According to Kalb et al. 2004.
[D. junghuhnii]
Guyana (Jansen-Jacobs 3510); picture length = 7 mm.

Diorygma poitaei (Fe) Kalb, Staiger & Elix (Graphina virginea (Eschw.) Mll. Arg.) - Ascocarps linear, immersed, rarely surrounded by a swollen thallus border; hymenium ca. 200-220 mu, clear, partly I+ blue; ascospores 8/ascus, muriform, I+ dark violet, ca. 80-100 x 16-20 mu. Major substance: hypostictic acid. Specimens studied: Sipman 9011, 51110, 51980. NOTE: The available specimens were without hymenium, except 51980, and therefore might as well belong to D. intermedium.
[D. poitaei] [D. poitaei]
Costa Rica (Sipman 51110); picture length = 7 mm. Costa Rica (Sipman 51141); picture length = 7 mm.
[D. poitaei]
Costa Rica (Sipman 51117); picture length = 7 mm.

Diorygma pruinosum (Eschw.) Kalb, Staiger & Elix - Ascocarps variously shaped, with exposed disc, immersed, surrounded by swollen thallus border; hymenium 100-150 mu, clear, I+ blue; ascospores 1(-2)/ascus, muriform, ca. 90-150 x 25-50 mu. Major substance: protocetraric acid. Specimen studied: Sipman 51666.
[D. pruinosum] [D. pruinosum]
Costa Rica (Sipman 51666); picture length = 7 mm. Colombia (Sipman 33288); picture length = 7 mm. Deviating form with elongated ascocarps.

Diorygma reniforme (Fe) Kalb, Staiger & Elix - Ascocarps variously shaped, with exposed disc, immersed, surrounded by swollen thallus border, with more or less constricted base; hymenium 150-200 mu, clear, I+ weakly blue; ascospores 1/ascus, muriform, ca. 110-230 x 35-80 mu. Major substances: norstictic, salazinic, protocetraric acids. Description according to Kalb et al. 2004. NOTE: Ascocarps resemble those of D. salvadoriense.
[D. reniforme]
in prep.

Diorygma salvadoriense Kalb, Staiger & Elix - Ascocarps variously shaped, with exposed disc, immersed, surrounded by swollen thallus border; hymenium 160-210 mu, clear, I- or I+ blue; ascospores 1/ascus, muriform, ca. 150-200 x 50-75 mu. Major substances: norstictic, salazinic acids. According to Kalb et al. 2004.
[D. salvadoriense]
El Salvador (E. Sandoval 581); picture length = 7 mm.

Diorygma sipmanii Kalb, Staiger & Elix - Ascocarps variously shaped, with exposed disc, immersed, surrounded by swollen thallus border; hymenium 150-200 mu, clear, I+ blue; ascospores 2-5/ascus, muriform, ca. 45-100 x 14-30 mu. Major substance: hypostictic acid. According to Kalb et al. 2004.
[D. sipmanii]
El Salvador (Sipman 44856); picture length = 7 mm.