Meriderma carestiae (Ces. & De Not.) Mar. Mey. & Poulain, 2011

Moreno, Gabriel, Villalba, Angela López, Castillo, Aurelio & Stephenson, Steven L., 2018, Some nivicolous species of Lamproderma and Meriderma from the Himalayan Mountains of northwestern India, Phytotaxa 373 (3), pp. 221-230 : 228-229

Meriderma carestiae (Ces. & De Not.) Mar. Mey. & Poulain , in Poulain, Meyer & Bozonnet, Myxomycètes: 551

(2011) Fig. 7

≡ Lamproderma carestiae (Ces. & De Not.) Meyl., Bull. Soc. Vaud. Sci. Nat. 57: 368 (1932)

≡ L. cribrarioides var. carestiae (Ces. & De Not.) G. Moreno & H. Singer , in Sánchez, Moreno, Illana & Singer, Bol. Soc. Micol. Madrid 31: 182 (2007)

Sporocarps stalked, 1.5–2 × 0.5–1.1 mm. Sporotheca ellipsoidal to pyriform, rarely globose. Stalk blackish, up to one half the total height of the sporocarp, broad at the base. Peridium blackish, not iridescent, without macules, with irregular dehiscence that leaves small more or less circular plates visible with a hand lens. Columella blackish brown, thick, attaining up to half of the height of the sporotheca. Capillitium dark brown, dense and branched, with funnel- or Y-shaped terminations. These extremities can be clearly observed under SEM. Spores (10)10.3–12 × (10)10.2–11.5 μm in diam, av. 11.3 × 10.9 μm, Q av = 1–1.03–1.09, n = 25, globose to subglobose, blackish in mass, brown-violet in transmitted light, warted to slightly spinulose. Under SEM the spore ornamentation is formed by baculae that frequently are fused into small linear crests, sometimes sinuous but without forming a reticulum or subreticulum.

Habitat: —Nivicolous, on decaying herbaceous plants near the edge of melting snowbanks.

Specimens examined: — INDIA. Himachal Pradesh Province: north of the city of Manali, 32°20’23.9 N, 77°13’08.2 E, 3240 m, 21 May 2006, leg. Stephenson 21254 in AH 46522.

Notes: —The genus Meriderma Mar. Meyer & Poulain ( Poulain et al. 2011) groups those species formerly placed in the genus Lamproderma in which fragments of the peridium remain attached to the extremities of the capillitium, thus appearing funnel-shaped or appearing to have Y-terminations. Previous molecular studies have indicated that these species form a clade that is different from Lamproderma ( Fiore-Donno et al. 2008) . This clearly monophyletic “ Meriderma ” clade is characterized by an early evanescent peridium. While drying up, the latter remains attached to the ends of the capillitium, which thus appear funnel-shaped ( Fiore-Donno et al. 2012). Two similar species are Meriderma cribrarioides (Fr.) Mar. Mey. & Poulain , which differs primarily in the reticulate ornamentation of the spores, and M. echinulatum (Meyl.) Mar. Mey. & Poulain , which has spiny spores.

Figures

FIGURE 7. Meriderma carestiae (Ces. & De Not.) Mar.Mey.& Poulain, (AH 46522). a. Sporocarps, b. Sporocarp by LM. c. Details of the columella and capillitium, d. Detail of the funnel-shaped or Y-terminations of the capillitium, e. Detail of the funnel-shaped terminations with remnants of the peridium present, f–h. Spores, i. Detail of spore ornamentation. Bars: a = 1 mm, b = 200 μm, c = 100 μm, d–e = 5 μm, f–h = 2 μm. i = 1 μm.