Agaricus lodgeae L.A. Parra, Angelini & B. Ortiz, 2018

Parra, Luis A., Angelini, Claudio, Ortiz-Santana, Beatriz, Mata, Gerardo, Billette, Christophe, Rojo, Carlos, Chen, Jie & Callac, Philippe, 2018, The genus Agaricus in the Caribbean. Nine new taxa mostly based on collections from the Dominican Republic, Phytotaxa 345 (3), pp. 219-271 : 236-239

Agaricus lodgeae L.A. Parra, Angelini & B. Ortiz , sp. nov. ( Figs. 6–7 )

MycoBank: MB823279.

Etymology: The specific epithet honors D. Jean Lodge, the first collector of this new species, for her contribution to the mycological knowledge of the Caribbean.

Original description, Macroscopic description: Pileus 2.5–4 cm diam., at first hemispherical-campanulate, sometimes with an inconspicuous obtuse umbo, finally plane, fully extended. Margin striate over more than half the radius of the pileus. Surface fibrillose, with purple fibrils on whitish background, disc strongly pigmented vinaceous red while margin remains constantly discolored and whitish. Surface stains purple violet on handling or at contact with raindrops. Lamellae free, crowded, somewhat wide and generally straight, intercalated with numerous lamellulae, at first rose, then blackish brown in mature basidiomata, with the edge whitish and irregular. Stipe 5–7 × 0.4–0.6 cm, more or less cylindrical, straight or more frequently curved or flexuose, tapered at apex, tending to enlarge towards the base where it ends in quite distinct rhizomorphs, with an annulus in its upper third, surface finely fibrillose, off-white and yellowing, with fibrils more evident above annulus. Annulus superous, undeveloped and fine, non-striate, cobweb-like or cortiniform in young basidiomata, sometimes incomplete and present only in fragments in the adults. Context scanty, when cut whitish, quickly yellowing and with odor of bitter almonds.

Microscopic description: Spores (4.46–)4.64–4.86–5.15 × 3.10–3.50–3.81 μm, Q=1.24–1.39–1.56, ellipsoid, smooth, brown, without apical pore. Basidia 10–15 × 6–8 μm, tetrasporic, clavate or slightly truncated at the apex, pyriform to globose near the lamellae edge, sterigmata up to 3 μm long. Cheilocystidia abundant, hyaline, generally simple, rarely septate at the base, clavate, pyriform or globose more or less pedunculated, terminal elements 13–32 × 10–18 μm, when septate anteterminal elements somewhat cylindrical of 5.5–12.0 × 5.5–7.0 μm. Pleurocystidia not observed. Lower surface of the annulus consisting of hyaline hyphae, cylindrical, not or slightly narrowed at the septa, 2–8 μm wide. Inflated elements not observed. Pileipellis a cutis, hyphae cylindrical, the wider the more constricted at septa, 4–10 μm wide. Terminal elements not observed. Clamp-connections not observed.

Macrochemical reactions: Schäffer’s reaction positive, slow but intense, color dark reddish purple. KOH reaction difficult to observe on the pileus because of the dark color of the dried material, reddish orange on the stipe base.

Habit, habitat, occurrence and distribution: In groups of few basidiomata, at times caespitose, deeply inserted into the leaf litter, in both broadleaf as mixed with conifers ( Pinus occidentalis ) forests; from lowland to the mountains. Very common. Recorded only from Puerto Rico and the Dominican Republic.

Species-specific ITS markers in A. subg. Minores : tttggTTTTTr(tt)gg@103–108. Other species have only 2T (rarely 3T or 4T)

Note: The original description is based on the Dominican collections. This species is also found in Puerto Rico, where three collections have been also made. These collections share the macroscopic characters with the Dominican ones, but they differ in their fungal or indistinct odor and spores that are somewhat longer in collections PR4634 and PR6454 (4.8–6.4 × 3.2–4 μm and 5–5.9 × 3.2–3.6 μm, respectively), but similar in collection PR6239 (4.3–5.6 × 3.2–3.6 μm). The collections from Puerto Rico will be fully described in a future work in preparation. We also found in GenBank an ITS sequence of a collection (PA393) from Panama that belongs to this taxon, in spite of its original identification as “ Lepiotaceae sp.” by Vo et al. (2009). This is a ubiquitous species of small to medium size, characterized by its fibrillose pileus with the disc strongly pigmented vinaceous purple and the whitish margin, the long off-white and yellowing flexuous stipe, and the fine, undeveloped, not-striate, sometimes incomplete or present only in fragments annulus.

Material examined: DOMINICAN REPUBLIC, Puerto Plata, Sosúa, Puerto Chiquito , 25 November 2011, JBSD123817 ( LAPAM14 ) ; La Vega, Jarabacoa, Jarabacoa , 10 January 2016, JBSD126505 Holotypus ( LAPAM67 Isotypus ) ; La Vega, Jarabacoa, Jarabacoa , 10 January 2016, JBSD126506 ( LAPAM68 ) . PUERTO RICO, Luquillo, Sabana Field Station , 31 August 1997, collector D. J. Lodge, PR4634 ( CFMR) ; Rio Grande, by El Verde Field Station trail, 31 August 2000, collector D. J. Lodge, PR6239 ( CFMR) ; Luquillo, Sabana Road 988, 1 km from Sabana Station , 29 September 2001, collector D. J. Lodge, PR6454 ( CFMR) .

Taxonomic comments: Although this species belongs to A. sect. Pantropicales within A. subg. Minores , it resembles to species of A. subg. Minoriopsis with purple pileus, such as A. argenteopurpureus , A. martinicensis or A. porphyropos . These three species differ in having a double annulus with a fibrillose-squamose lower surface and a pileus in fresh and young collections without a conspicuous striate margin. Furthermore, Agaricus martinicensis and A. porphyropos are more robust.

Additional comments: In the genus Agaricus , conspecific specimens generally have less than three differences in their ITS sequences. In A. lodgeae , certain samples such as LAPAM 14 and PR 6454 (top and bottom positons in Table 6), differ at eight positions and another sample (PR 4634) is heteromorphic at all 13 positions shown in this Table. An ancient hybridation between highly divergent populations might be at the origin of the highly variable population observed today.

Heteromorphisms in bold types: Y = C and T ; R = A and G ; S = C and G.

Figures

FIGURE 6. Macroscopic characters of A.lodgeae. A–F. Basidiomata.A.(JBSD123817);B–E.(JBSD126505, holotype);F.(JBSD126506). Photos by C. Angelini.

FIGURE 7. Microscopic characters of A. lodgeae. A–G. In ammoniacal Congo red. A, C, E–G. (JBSD123817), B, D. (JBSD126505, holotype).A–C. Cheilocystidia.D. Basidia (near the lamellae edge). E. Spores. F. Hyphae of the lower surface of the annulus.G. Pileipellis hyphae. Photos by L.A. Parra.