Marasmius odoratus V.A. Farook & Manim., 2015

Farook, V. Adnaan & Manimohan, Patinjareveettil, 2015, Marasmius odoratus-a new jasmine-scented species of Marasmius section Globulares from India, Phytotaxa 227 (3), pp. 275-281 : 277-279

Marasmius odoratus V.A. Farook & Manim. , sp. nov. Fig. 1. A–D

MycoBank 812904

Diagnosis: — Differing from Marasmius purpureostriatus Hongo in having a deeply sulcate pileus with grayish red grooves on a pale cream background, longer, pale cream to pale orange stipe, slightly smaller [17–23 (25) × 4–5 μm], narrowly clavate basidiospores, a fragrant odor recalling jasmine flower, and a distinctive ITS sequence ( KT180332 ). Holotype: — INDIA. Kerala State: Palakkad District, Silent Valley National Park, Walakkad section, on the way to Sisspara , 22 October 2013, V. Adnaan Farook, AF519 ( CAL 1264 ).

Etymology:—The specific epithet refers to the odoriferous basidiomata of this species.

Description:—Basidiomata medium-sized. Pileus 35–49 mm diam., broadly campanulate; surface pale cream at the disc and on the ridges, grayish red with a violaceous tint (12E5/OAC504) in the grooves; deeply sulcate, with conspicuous radial ridges that are regularly forked towards the margin, dry, glabrous; margin straight or slightly upturned, entire. Context up to 2 mm thick at the center, thin and membranous elsewhere, whitish, sometimes with pale violaceous tint. Lamellae adnexed, distant (11–12), up to 3 mm wide, with lamellulae in 2–3 tiers, pinkish white (12A2/OAC487) or pale cream; edge entire, concolorous with the sides. Stipe 107–165 × 3–3.5 mm, central, terete, equal except for the base, hollow; surface pale cream to pale orange (5A3/OAC794), glabrous; base somewhat bulbous (4–8 mm), non-insititious, with pale cream colored basal mycelium and mycelial strigosity on the bulbous region. Odor distinctive, fragrant, like that of jasmine flower. Spore print white.

Basidiospores 17–23(–25) × 4–5 (20.8±1.99 × 4.4±0.4) μm, Q = 3.8–5.8, Qm = 4.8, narrowly clavate, smooth, thin-walled, hyaline, inamyloid. Basidia not observed. Basidioles abundant, 28–51 × 6–7 μm, mostly narrowly clavate to clavate or cylindric-clavate, thin-walled, hyaline. Lamella edge sterile, bearing numerous cheilocystidia that resemble the pileipellis elements. Cheilocystidia 17–26 × 8–16 μm, versiform: clavate, broadly clavate or obpyriform, often pedicellate, slightly thick-walled (up to 0.5 μm), smooth, hyaline. Pleurocystidia none. Hymenophoral trama subregular; hyphae 2–9.5 μm wide, thin- to slightly thick-walled, hyaline with occasional hyaline spiral encrustations, dextrinoid. Pileus trama interwoven; hyphae 2–8 μm wide, thin- to slightly thick-walled, hyaline, dextrinoid. Pileipellis a hymeniform layer of Globulares - type cells; cells 15–42 × 10–17 μm, versiform: clavate, broadly clavate, ellipsoid, obovate, sphaero-pedunculate, often pedicellate, sometimes catenulate, thin-walled, hyaline. Stipitipellis a cutis with closely septate hyphae; hyphae of 41–145 × 9–15 μm, hyaline, thick-walled cells. Stipe trama dextrinoid. Clamp connections present on all hyphae, often loop-like.

Additional collection examined:— INDIA. Kerala State: Palakkad District, Silent Valley National Park, Walakkad section, 29 October 2011, V. Adnaan Farook, AF213 (CAL 1263).

Habitat:—On the forest floor, amongst leaf litter, scattered.

Geographical distribution range:—Currently known only from the type locality in Kerala State, India.

Comments: — The central, well developed, non-insititious stipe, the non-collariate lamellae, the smooth pileipellis elements and the dextrinoid context places this species in Marasmius section Globulares . There are a few Asian species of sect. Globulares that have a strongly sulcate pileus with purplish striae, distant lamellae, and large basidiospores. These include Marasmius purpureostriatus Hongo (1958: 344) , M. pseudopurpureostriatus Wannathes, Desjardin & Lumyong ( Wannathes et al. 2009a: 162), and M. albopurpureus T.H. Li & C.Q. Wang ( Wang et al. 2015: 32). None of these species are reported to have a diagnostic odor.

Marasmius purpureostriatus , firstly reported from Japan and subsequently from Malaysia ( Tan et al. 2009), Thailand ( Wannathes et al. 2009b), and South Korea (Antonín et al. 2010), differs from the new species in having a pileus with a dark violet sulci, a brown to reddish brown stipe, larger basidiospores [(19–)21–30 × (4–)5–6(–7) μm] and smaller pileipellis elements (12–27 × 8–14 μm). Marasmius pseudopurpureostriatus from Thailand differs in having wider, pale yellow to grayish yellow ridges on the pileus, very distant lamellae with less series of lamellulae, a grayish magenta color at the stipe apex, and larger basidiospores (20–25 × 5–6.2 μm). Marasmius albopurpureus , a species recently described from Baili Island in South China Sea, differs in having a pileus with depressed center and inrolled margin, poorly developed, very distant lamellae often without lamellulae, and a stipe that is violet colored towards the apex. Marasmius musisporus Desjardin & Horak (1997: 15) from Papua New Guinea also has a strongly sulcate pileus with a grayish lilac disc and furrows, distant lamellae (11–14), and elongate basidiospores. However, it has much longer basidiospores (30–40 × 4.5–5 μm), shorter and slender stipe (50–70 × 1–1.5 mm), and basidiomata with non-distinctive odor. Marasmius bekolacongoli Beeli (1928: 157) , a tropical African species, is similar to the new species in the deeply sulcate, campanulate pileus, the long stipe, and the basidiospore size, but differs in having a larger (up to 100 mm diam.), pellucid striate, lemon yellow pileus with a violaceous disc and radial striae, yellowish white to pale lemon yellow lamellae, a stipe that is longitudinally grooved and chestnut brown when old and shorter pileipellis elements (10–25 μm) ( Pegler 1977; Antonín 2007). Marasmius staudtii Hennings (1895: 97) , a species described from Cameroon and which according to Desjardin & Horak (1997) may be conspecific with M. purpureostriatus , differs in having larger basidiospores (20–28.5 × 4.5–6 μm) and well developed pleurocystidia ( Antonín 2007). Marasmius staudtii var. magnisporus Antonin (2007: 76) has still larger basidiospores (32–44 × 5.5–7.5 μm). Marasmius jasminodorus Wannathes, Desjardin & Lumyong ( Wannathes et al. 2009b: 264) is the only species of Marasmius that has a similar odor. That species, however, has a dark reddish brown pileus, smaller (9–14 × 3–4.5 μm), ellipsoid basidiospores, and Siccus - type broom cells on the lamella edge, pileipellis and stipitipellis.

Comparison of ITS sequence generated from the Kerala collection with the sequences available in GenBank indicates that M. odoratus is a distinct species. In a Megablast search of the GenBank database (accessed on 17 August, 2015) using the ITS sequence of M. odoratus , the closest matches included Marasmius species NKZ-2014 (KJ126766) from China (93% identity); Marasmius species 4 GMB-2014 (KP012759) from Australia (92%), M. galbinus T.L. Li & Chun Y. Deng from China (HQ709445, 92%), M. grandiviridis Wannathes, Desjardin & Lumyong from Thailand (EU643514, 92%) M. laticlavatus Wannathes, Desjardin & Lumyong from Thailand (EU643511, 92%), M. puerariae R. Kirschner from Taiwan (JX470333, 91%) and M. purpureostriatus from Thailand (EU935539, 91%) and South Korea (FJ904978, 90%). MP analysis yielded a phylogenetic tree ( Fig. 2 ) that depicted the relative placement of M. odoratus within the genus. The tree revealed that M. odoratus is nested within a clade consisting of Marasmius species NKZ-2014, M. purpureostriatus , M. pseudopurpureostriatus , M. grandiviridis , and M. puerariae . Within that clade, M. odoratus formed a distinct lineage sister to M. puerariae with weak support. Marasmius puerariae is a parasitic species reported from Taiwan, exclusively associated with living leaves of Pueraria montana ( Kirschner et al. 2013) . That species has tiny basidiomata with a pileus striped with paler, greenish gray ridges and dark purplish sulci and larger basidiospores (25–28 × 5–6 μm). Marasmius galbinus has a pileus with greenish white disc and striae, smaller basidiospores (14–16 × 4–5 μm), irregularly clavate cheilocystidia and versiform caulocystidia. Marasmius grandiviridis has larger (37–88 mm diam.), yellowish green pileus, larger basidiospores (26–30 × 4–5 μm) and irregularly clavate to lageniform-mucronate cheilocystidia. Marasmius laticlavatus has a pileus with a brown disc and grayish cream margin and much larger basidiospores (26–35 × 5–7 μm).

Figures

FIGURE 1. A–D: Marasmius odoratus (CAL 1264). A. Basidiomata; B. Basidiospores; C. Cheilocystidia; D. Pileipellis. Scale bars: A = 10 mm; B–D = 10 μm. Photos: V. Adnaan Farook.

FIGURE 2. MP phylogram using ITS sequence data. Values in the branches indicate the BS support. BS values greater than 50% are shown. GenBank accession numbers are given after the name of each taxon.