Perichaena quadrata T. Macbr.

Baba, Hayri, 2021, Five new Myxomycetes (Myxogastria) records from Turkey, Phytotaxa 507 (2), pp. 131-143 : 135-141

Perichaena quadrata T. Macbr. ( Fig. 4 )

Synonyms: Perichaena depressa var. quadrata (T. Macbr.) Torrend

Description: —Sporocarps sessile sporangium or plasmodiocarps, very small, 0.3–1 mm diameter, crowded, polygonal or quadrangular, depressed, but not flattened, rarely single, usually appressed with polyhedral shape, discoid, sometimes lengthened, smooth, bright rufous or brown, purple-brown or entirely black, becoming pseudoaethalioid with lateral walls fused and sporotheca tops forming a continuous areolate surface, sometimes in ones or twos but more usually heaped in clusters of 3–20. Sporothecae varying from depressed-pulvinate to globose, 0.1–0.5 mm diameter, bicolored, the upper part dull reddish- to pale yellowish brown. Hypothallus extended under the sporocysts, dark brown. Peridium double, dark red-brown, shiny, somewhat iridescent, dehiscence as a flap, which allows to see the inner colour of the bright yellow spore mass at the edges, above the dehiscence line, outer layer cartilaginous, opaque, thickened with spheroidal matter and closely adhering to the inner, pale yellow, faintly papillose layer, rather thick, yellow within, dehiscence circumscissile. Capillitium scanty, of slender, sparingly branched filaments, surface minutely roughened, warted or spinulose; below the dehiscence line the peridium is single, membranous, hyaline and without deposits, forming a lax reticulum of pale yellow threads, 1.5–3 µm diameter, with close-set constrictions at regular intervals. Spore-mass golden yellow. Spores globose to subglobose, pale yellow, 9–11(–12) µm diameter, with warts minutely spinulose.

Specimen examined: — Adana Ceyhan , on rotting woods, moist chamber technique, 37° 02’17” N, 35°48’19”E, 24 m, 24.02.2021, Baba 8 .

Distribution: —North America ( Lado 1994), France, Spain, Italy ( Compagno et al. 2012), Argentina, Chile, Mexico, Panama and Peru ( Lado et al. 2013, 2014, Estrada-Torres et al. 2009).

Comments: — Perichaena in Arcyriaceae has six species in Turkey ( Baba & Sevindik 2019, Baba et al. 2021a). This species is easily recognisable because of its rounded and convex sporocarps, sometimes with a tendency to form short plasmodiocarps, bright reddish brown, threads of the capillitium irregular and covered with an evident reticulum. P. quadrata and P. depressa are difficult to distinguish being morphologically close to one another, occupying the same habitats and occasionally forming sporangia in close association ( Keller & Eliasson 1992). P. quadrata has depressed to pulvinate or globoid sporocarps, not markedly flattened as occurs in P. depressa , with small dimensions of the sporotheca and the capillitial threads, mostly with reticulate ornamentation (very difficult to see in some cases); all these features are noted by Keller & Eliasson (1992) as the differentiating characters of P. quadrata ( Lado et al. 2019) . The white crystalline encrustation (calcium oxalate) sometimes seen in fructifications of P. depressa was never observed in P. quadrata , although the two taxa were grown on the same medium ( Keller & Eliasson 1992). P. depressa is easily recognized by the peculiar, polygonal, depressed-flattened sporangia and consequent shallow spore-cases in which lie the yellow spores and scanty capillitium ( Cavalcanti et al. 2015). P. corticalis and P. depressa are similar. P. corticalis can be distinguished by the larger spores (12–14 μm diameter) and the dehiscence occurring along a whole circular lid developed on the middle of the sporocarp. On the other hand, P. depressa develops flat and wider (0.5–1.5 mm diameter) sporocarps, and its spores are 8.5–10 μm diameter, a range which overlaps with P. quadrata ( Mitchell 1978, Lizárraga et al. 2015). Keller & Eliasson (1992) concluded that P. depressa shows pitted and spinulose capillitium threads, whilst P. quadrata shows a low reticulum covering them.

Order: Physarida

Family: Didymiaceae

Diderma spumarioides (Fr. & Palmquist) Fr. ( Fig. 5 )

Synonyms: Didymium spumarioides Fr. & Palmquist

Physarum stromateum Link

Chondrioderma spumarioides var. didermoides Rostaf.

Chondrioderma virgineum Massee

Diderma concavum Emoto

Description: —Fruiting body, a sessile sporangium, rather small, densely clustered, irregularly globose, subglobose, spherical, or by mutual pressure, 0.4–0.8 mm diameter, white or pale ochraceous, deeply embedded in a thick, white, calcareous hypothallus, seated close together on a strongly developed whitish or yellowish creamy common hypothallus. Hypothallus more or less plainly in evidence, white to cream coloured. Peridium double, the outer layer thickly calcareous but very frail, almost farinaceous, rough, fragile, wall white to pale ochraceous, rugulose, covered by a dense farinaceous layer of lime, closely attached to the inner, the inner layer membranous, dull grey, layer sometimes scarcely developed, dehiscence irregular. Columella convex or hemispherical, roughened, globose to pulvinate, whitish, white or yellowish, calcareous. Capillitium abundant of brown threads with pale tips, 1–2(–4) µm diameter, of slender colorless threads, ornamented with occasional nodules, sparsely branched and anastomosed, ascending from the columella. Spore-mass black. Spores globose, pale yellow-brown, violaceous, 8–11 µm diameter, minutely or irregularly warted or verruculose, spiny. Plasmodium white.

Specimen examined: — Adana (Karatas), on rotting leaves debris and humus soil, Natural , 36°34’39”N, 36°22’43”E, 41 m, 11.05.2020, Baba 8 .

Distribution: — Taiwan ( Chung & Liu 1998), Britain and Ireland ( Ing 1999), New Zealand ( Stephenson 2003), Bolivia, Belgium, Canada, Chili, Ecuador, Germany, Portugal USA, Venezuela ( Buyck 1988), Argentina ( Lado et al. 2014), Crimea, Ukraine ( Moreno et al. 2017).

Comments: — Didymiaceae contains 4 genera and 37 species. Diderma has 12 species recorded in Turkey ( Baba & Sevindik 2019, Baba et al. 2021a), and easily recognized by the double wall, and smooth crustaceous layer of lime on the outer surface of the sporangium. Sessile, several hundreds of sporangia are irregularly globose, subglobose, spherical, white or pale ochraceous. Columella convex or hemispherical, roughened, globose to pulvinate, whitish, white or yellowish, calcareous. Capillitium brown threads with pale tips, colorless threads, ornamented with occasional nodules. D. spumarioides is similar to D. globosum , D. crustaceum and D. cinereum but spore size and peridial layers are different ( Martin & Alexopoulos 1969). Separated from D. globosum by the closely appressed peridial layers and the thick, embedding hypothallus and from D. cinereum in the rough peridium hypothallus and spore colour ( Ing 1999). Densely crovded sporangia deeply embedded in a prominent, white hypothallus make this an easy species to identify ( Stephenson 2003). Some specimens of D. spumarioides possess a capillitium that branches more irregularly and where the threads are shorter and more slender, thus more like those of D. cinereum or D. donkii ( Buyck 1988) . D. cinereum is distinguished by its very slender and flexuous capillitium that is not formed by hyaline straight filaments, while D. globosum has a distinctly double peridium with widely separated layers, and D. spumarioides has a peridium which appears to be single (sometimes clearly double) but with both layers always adhering very closely ( Moreno et al. 2017). The taxonomic characters of this species exhibit considerable variation and it is difficult to establish satisfactory diagnostic criteria ( Lado et al. 2019). D. spumarioides usually differs from D. cingulatum and D. subviridifuscum in the sparser arrangements of the sporocysts. Peridium and hypothallus exhibit less lime incrustation and the capillitium adheres more firmly to the peridium, which splits up in larger fragments ( Buyck 1988). Many specimens of D. spumarioides and D. subviridifuscum exhibit a spiky columella and capillitium with distinct radiating, fusiform lime incrustations. Features of typical capillitium, like the presence of typical lenticular swellings, the firm habit and the sparse branching of the threads, which posses a distinct lumen in optical section, are very useful indications of D. spumarioides .

Family: Physaraceae

Craterium aureonucleatum Nann. -Bremek ( Fig. 6 )

Synonym: Craterium aureonucleatum var. heterobaculatum Oltra

Description: —Sporocarps short-stalked or sessile sporangium, in small groups, 0.5 mm tall. Sporothecae subglobose sub-conical or turbinate, 0.3–0.5 mm diameter, dull orange-brown. Hypothallus large, membranous, orange, white, discoid, like a wide membranous disk, ridged. Stalk up to 0.2 mm long, grooved, dark orange and clear. Peridium of two layers, the inner layer membranous, the outer layer thicker, pale orange below, yellow above, the upper part with white calcareous granules, often with yellow crystalline discs inside, apex forming a convex lid, the inside papillate, cup rim torn and irregular. Capillitium a net with small meshes and numerous small, angular, often branched, white or yellow nodes which mass together in the centre to form an orange-yellow pseudocolumella, the nodes sometimes contain yellow crystalline discs. Spore-mass dark brown. Spores dark lilac-brown, 9–10 µm diameter, verruculose covered by light tiny warts.

Specimen examined: — Hatay (Antakya), on bark of Eucalyptus sp. and rotting leaves and debris, Natural , 36°19’59” N, 36°11”51” E, 120 m, 30.12.2020, Baba 1, 2, 5 .

Distribution: —Canary Islands, England, Germany, Netherland, and Scotland (Nannenga- Bremekamp 1991, Ing 1999, Beltrán et al. 2004), Italy ( Compagno et al. 2012).

Comments: —Family Physaraceae contains 8 genera and 63 species, with Craterium having 4 species in Turkey ( Baba & Sevindik 2019, Baba et al. 2021a). C. aureonucleatum has a conical shape and small nodes, sporocysts are described as subglobose, not subconical. Stalk and the outer layer of peridium below pale orange, dark orange and clear. C. aureonucleatum differs from C. leucocephalum in the conical shape and smaller nodes, sporocysts are described as sub-globose, not sub-conical. Stalk and the outer layer of peridium below pale orange, dark orange and clear ( Ing 1999). The sporophore morphology of this species may differ slightly from the original definition of Ing (1999), where sporocysts were defined as sub-conic. This difference may be due to ecological conditions and infraspecific variability ( Compagno et al. 2012).

As a result of this research, five new records were added to Myxobiota of Turkey. The number of recorded Mycetozoa taxa in Turkey has increased to 296.

Figures

FIGURE 4. Perichaena quadrata. a, b, c. Sporangia. d, e, f. Capillitium and spores.

FIGURE 5. Diderma spumarioides. a, b, c. Sporophores. d. Capillitium and lime granules. e, f. Capillitium and spores.

FIGURE 6. Craterium aureonucleatum. a–d. Sporangia. e, f. Capillitium, lime granules and spores.