Phenotypic studies

Morphological characterisation of the fungal isolates was carried out based on cultures grown on oatmeal agar (OA; filtered oat flakes after 1 h of simmering, 30 g; agar, 20 g; distilled water to final volume of 1 000 mL) and 2 % potato dextrose agar (PDA; Pronadisa, Madrid, Spain). Cultures were incubated at 25 ± 1 °C in the dark and periodically examined each 7 d up to 4 wk. Colony diameters were measured after 14 d of growth, and colony colours determined using the colour charts of Kornerup & Wanscher (1978). In addition, the ability of the isolates to grow at 15, 20, 25, 30, 35, 37 and 40 °C was determined on PDA. Microscopic features were examined and measured by making direct wet mounts with 85 % lactic acid or lactophenol cotton blue or by slide cultures on OA, using an Olympus CH-2 light microscope (Olympus Corporation, Tokyo, Japan). Photomicrographs were made with a Zeiss Axio-Imager M1 light microscope (Zeiss, Oberkochen, Germany), using phase contrast and Nomarski differential interference. Scanning electron microscope (SEM) micrographs were obtained with a Jeol JSM-6400 scanning electron microscope (JEOL, Peabody, MA, USA) using techniques described previously (Figueras & Guarro 1988).

Taxonomy

On the basis of the phylogenetic analysis we conclude that the species resolved here as Sarocladium sp. I–VI represent undescribed taxa. In addition, A. terricola, for a long time left in the limb of synonymy is re-considered as a distinct species, better accommodated in Sarocladium, hence the new combination S. terricola is proposed; in addition, the new combination S. implicatum is also proposed for A. implicatum.

Sarocladium bifurcatum Giraldo, Gené & Deanna A. Sutton, sp. nov. — MycoBank MB807943; Fig. 2

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Fig. 2

Sarocladium bifurcatum (sp. III) UTHSC 05–3311. a, b. Colonies on OA and PDA, respectively, after 14 d at 25 °C; c. simple and branched conidiophores; d. schizophialides; e. phialide with periclinal thickening at the apex producing conidia in chains and adelophialide (arrow); f, g. fusiform conidia with slightly truncate ends. — Scale bars: c–f = 10 μm; g = 5 μm.

Etymology. Refers to the presence of phialides with a bifurcate apex.

Colonies on OA at 25 °C attaining 14–18 mm in 14 d, greyish orange (5–6B3) at the centre and brownish orange (7C4) toward the margin, flat, powdery. On PDA at 25 °C attaining 13–14 mm in 14 d, orange white (5A2), rugose, slimy. Vegetative hyphae septate, hyaline, smooth- and thin-walled, 1–1.5 μm wide. Conidiophores erect, usually simple, straight or slightly bent, up to 75 μm long, hyaline, smooth-walled. Phialides subulate, 17–43 μm long, 1–2 μm wide at the base, with distinct apical periclinal thickening, hyaline, thin- and smooth-walled; adelophialides sometimes present; schizophialides commonly present. Conidia unicellular, fusiform, 4–6 × 1–2 μm, with slightly truncate ends, initially hyaline and smooth-walled, becoming subhyaline and apparently rough-walled due to the production of a mucilaginous exudate, arranged in chains. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth — Optimum 20–25 °C, maximum 30 °C, minimum 15 °C, no growth at 35 °C.

Specimens examined. INDIA, Bangalore, Hortus Lal Bagh, on a dead stem of bamboo, Jan. 1973, W. Gams, CBS 383.73 = FMR 12316. – USA, Texas, from bronchoalveolar lavage fluid, 2005, D.A. Sutton (holotype CBS H-21627, culture ex-type CBS 137658 = FMR 10405 = UTHSC 05-3311); from bronchial wash fluid, 2007, D.A. Sutton, UTHSC 07-3446 = FMR 10451.

Notes — No phenotypic differences were observed among the three isolates of S. bifurcatum studied here; however, the two clinical specimens showed some genetic distance in the three regions analysed with respect to that isolated from bamboo (2–2.2 %), suggesting that two different species could be represented by this clade. The isolate CBS 383.73 was originally identified as Paecilomyces ochraceus (currently S. ochraceum), but it can be clearly differentiated from this latter species by its growth rate and the colony colour on OA after 14 d (14–18 mm and greyish to brownish orange vs 30 mm and ochraceus in S. ochraceum), by the abundance of schizophialides and by the inability to grow at 37 °C. Although in the phylogenetic analysis (Fig. 1) S. bifurcatum constituted a sister clade of S. glaucum, both species can be clearly differentiated as mentioned above by the colour of the colony, which is intensely grey-green to bluish green in the latter species and greyish orange in the former.

Sarocladium gamsii Giraldo, Gené & Guarro, sp. nov. — MycoBank MB807944; Fig. 3

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Fig. 3

Sarocladium gamsii (sp. II) CBS 703.73. a, b. Colonies on OA and PDA, respectively, after 14 d at 25 °C; c, d. simple conidiophores; e. phialide with periclinal thickening at the apex; f. conidia arranged in slimy heads; g. conidia arranged in chains; h, i. fusiform conidia. — Scale bars = 10 μm.

Etymology. Named in honour of the eminent Austrian mycologist Walter Gams.

Colonies on OA at 25 °C attaining 12–20 mm diam in 14 d, white (1A1), flat, at first glabrous becoming powdery at centre. On PDA at 25 °C reaching 13–21 mm diam in 14 d, yellowish white (4A2), radially folded, umbonated, powdery. Diffusible pigment absent. Vegetative hyphae septate, hyaline, smooth- and thin-walled, 1.5–2 μm wide. Conidiophores erect, arising directly from vegetative hyphae or ropes of hyphae, straight or slightly bent, simple or poorly branched, up to 55 μm long, hyaline, smooth-walled. Phialides acicular, 18–45 μm long, 1–1.5 μm wide at the base, with distinct apical periclinal thickening, hyaline, thin- and smooth-walled; adelophialides and schizophialides not observed. Conidia unicellular, fusiform, 3–5 × 1–2 μm, hyaline to subhyaline, thin- and smooth-walled, arranged in both slimy heads and chains. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth — Optimum 20–25 °C, maximum 30 °C, minimum 15 °C. No growth at 35 °C.

Specimens examined. SRI LANKA, Paradeniya, Royal Botanical Garden, from dead stem of Pandanus lerum, Jan. 1973, W. Gams (holotype CBS H-8197), culture ex-type CBS 707.73 = FMR 11419; from a dead petiole of Pandanus lerum, Jan. 1973, W. Gams, CBS 425.73 = FMR 12432.

Notes — Although the two isolates of S. gamsii were obtained from the tropical palm P. lerum at the same time and place, they were originally identified as S. glaucum (CBS 425.73) and S. implicatum (CBS 707.73A), respectively. We did not find any phenotypic differences between these isolates. Genetically, they showed an overall similarity of 98.6 % for the three loci analysed. Sarocladium gamsii can be differentiated from S. glaucum and S. implicatum mainly by their colony colour, yellowish white in the former, intensely grey-green to bluish green in S. glaucum and pinkish white in S. implicatum; and by the conidial arrangement, which is in chains and slimy heads in S. gamsii, and exclusively in chains in S. glaucum and S. implicatum.

Sarocladium hominis Giraldo, Gené & Deanna A. Sutton, sp. nov. — MycoBank MB807945; Fig. 4

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Fig. 4

Sarocladium hominis (sp. VI). a, c. UTHSC 04–1034; b, d, h, i. UTHSC 04–3464; e–g, j. UTHSC 02–2564. a. Colonies on OA after 14 d at 25 °C; b, c. colonies on PDA after 14 d at 25 °C; d–g. simple and branched conidiophores with conidia arranged in slimy heads; h. phialides with periclinal thickening at the apex; i, j. cylindrical conidia. — Scale bars = 10 μm.

Etymology. Refers to the origin of the isolates, namely from human specimens.

Colonies on OA at 25 °C attaining 41–50 mm in 14 d, yellowish white (1A2), flat, usually fasciculate at the center and glabrous toward the periphery. On PDA at 25 °C attaining 22–30 mm in 14 d, orange white (5A2), slightly wrinkled or cerebriform, glabrous or fasciculate. Vegetative hyphae septate, hyaline, smooth- and thin-walled, 1–1.5 μm wide. Conidiophores erect, arising directly from vegetative hyphae or from ropes of hyphae, simple or poorly branched, straight, hyaline, smooth-walled, up to 45 μm long. Phialides acicular, 22–37 μm long, 1–2 μm wide at the base, with distinct periclinal thickening on the conidiogenous locus, thin- and smooth-walled, hyaline; adelophialides and schizophialides not observed. Conidia unicellular, cylindrical with rounded ends, 3–4(–7) × 1–1.5 μm, hyaline to subhyaline, thin- and smooth-walled, arranged in slimy heads. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth — Optimum 20–25 °C, maximum 35 °C (UTHSC 04-1034 and UTHSC 02-2564) or 37 °C (UTHSC 04-3464), minimum 15 °C. No growth at 40 °C.

Specimens examined. USA, Florida, from right calf tissue, 2004, D.A. Sutton (holotype CBS H-21628, culture ex-type CBS 137659 = FMR 10418 = UTHSC 04-1034); Alaska, isolated from leg, 2002, D.A. Sutton, FMR 10352 = UTHSC 02-2564; Texas, from sputum, 2004, D.A. Sutton, FMR 10425 = UTHSC 04-3464.

Notes — Sarocladium hominis together with S. kiliense, S. oryzae and S. zeae formed a clade morphologically characterised by cylindrical or ellipsoidal conidia arranged in slimy heads. Sarocladium kiliense differs in the formation of chlamydospores, adelophialides and appears as dirty orange to pale ochraceous colonies on OA; S. zeae has longer (up to 80 μm) and branched conidiophores with basitonous whorls of phialides; and S. oryzae produces white and cottony colonies, gnarled hyphae and longer (up to 82 μm) and repeatedly branched conidiophores. Although the three isolates of S. hominis are from clinical origin, the pathogenicity of such isolates remains to be proven. However, this species could be considered as a potential agent of human infections because of its ability to grow at 35–37 °C, and the deep tissue origin of the isolates.

Sarocladium implicatum (J.C. Gilman & E.V. Abbott) Giraldo, Gené & Guarro, comb. nov. — MycoBank MB807946

Basionym. Monilia implicata J.C. Gilman & E.V. Abbott, Iowa State Coll. J. Sci. 1: 269. 1927.

≡ Acremonium implicatum (J.C. Gilman & E.V. Abbott) W. Gams, Trans. Brit. Mycol. Soc. 64: 394. 1975.

≡ Sagrahamala implicata (J.C. Gilman & E.V. Abbott) Subram., Kavaka, 5: 98. 1977.

Colonies on OA at 25 °C attaining 38–45 mm in 14 d, yellowish white (4A2), flat, powdery. On PDA at 25 °C attaining 18–30 mm in 14 d, pinkish white (7A2) to salmon (6A4), raised, woolly or downy, reverse pale orange (6A5). Conidiophores erect, simple, hyaline, smooth-walled. Phialides solitary, straight or slightly flexuous, subulate, 15–30 μm long, 1–2 μm wide at the base, with distinct periclinal thickening of the conidiogenous locus, hyaline, thin- and smooth-walled. Adelophialides and schizophialides not observed. Conidia unicellular, fusiform, 5–8 × 1–2 μm, hyaline, smooth- and thin-walled, arranged in long dry chains. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth —Optimum 20–25 °C, maximum 37 °C, minimum 15 °C. No growth at 40 °C.

Specimens examined. EGYPT, desert soil, Nov. 1972, J. Mouchacca (neotype designated here CBS H-21634, MBT177687), culture ex-neotype CBS 959.72 = ATCC 32210 = FMR 12360 = IHEM 3713. – INDIA, from Saccharum officinarum, Nov. 1973, V.P. Agnihotri, CBS 825.73 = FMR 11418. – JAMAICA, from S. officinarum, Mar. 1970, W. Gams, CBS 397.70A = FMR 11422 = IMI 131645.

Notes — The three isolates of S. implicatum showed the same morphological features that Gilman & Abbott (1927) described in the protologue of Monilia implicata. This is the main reason why we prefer maintaining the epithet of the species rather than to introduce a new one. Although Gams (1975) examined a possible holotype of M. implicata (BPI 1769), presently it has been impossible to trace that material in the U.S. National Fungus Collections (Herbarium BPI, Farr & Rossman 2014). Therefore, designation of a neotype would stabilize the species concept. We have selected CBS 959.72 as neotype because, despite the fact that it does not originate from the same country than the type specimen of M. implicata, the CBS strain was isolated from the same substratum. Monilia implicata was originally described from soil in the USA (Gilman & Abbott 1927).

Monilia implicata and A. terricola were for a long time considered as conspecific (Gams 1975) and synonyms. However, our study showed that isolates morphologically identified as A. implicatum are dispersed into several clades, some of them distant from the ex-type strain of A. terricola (CBS 243.59). It is clear that A. implicatum and A. terricola represent different species within Sarocladium. Both species are morphologically similar, but they can be differentiated by the colour and the texture of the colonies on PDA, being white and cottony in S. terricola and pinkish to salmon and woolly or downy in S. implicatum; the lower limits of conidial and phialide length, which are slightly shorter in S. terricola (4 μm and 12 μm, respectively) than in S. implicatum (5 μm and 15 μm, respectively), and the maximum temperature for growth, which is 35 °C in S. terricola and 37 °C in S. implicatum. In addition, adelophialides and schizophialides are sometimes present in S. terricola but absent in S. implicatum.

In our phylogenetic tree S. ochraceum clustered as sister to S. implicatum, but the former species can easily be distinguished based on the production of ochraceous-yellow colonies on OA, usually branched conidiophores, and smaller phialides (15–26 μm long) and conidia (4.5–5 μm long). In contrast, S. implicatum produces yellowish white colonies on OA, and longer solitary phialides (up to 30 μm long) and conidia (up to 8 μm long).

Sarocladium oryzae (Sawada) W. Gams & D. Hawksw., Kavaka 3: 57. 1976 (‘1975’) — MycoBank MB323106

Basionym. Acrocylindrium oryzae Sawada, Rep. Gov. Res. Inst. Dept. Agric. Formosa 2: 135. 1922.

= Sarocladium attenuatum W. Gams & D. Hawksw., Kavaka 3: 59. 1976 (‘1975’).

= Cephalosporium caerulens Matsumae, Kamio & Hata, J. Antibiotics 16: 236. 1963, nom. inval. (Art. 36, 37).

Specimens examined. INDIA, Hyderabad, from O. sativa, Apr. 1973, K.S Amin (epitype designated here CBS H-466, MBT177330, culture ex-epitype CBS 180.74 = IMI 176759); Bangalore, from O. sativa, 1973, V. Agnihothrudu, CBS H-467, CBS 399.73 = IMI 184922. – NIGERIA, Ibadan, from O. sativa,July 1981,G.N. Ngala, CBS 414.81. – TAIWAN, Taipei, Taiwan National University, from O. sativa, K. Sawad (TAI, holotype of Acrocylindrium oryzae; IMI 189860, slide ex-holotype).

Notes — Sarocladium oryzae, previously described as Acrocylindrium oryzae (Sawada 1922), is a common pathogen of rice (O. sativa) and different species of bamboo (Bambusa balcooa, B. tulda, B. vulgaris) (Gams & Hawksworth 1975, Boa & Brady 1987, Bridge et al. 1989, Pearce et al. 2001, Ayyadurai et al. 2005). It has been reported to cause sheath-rot of rice in many countries (Sakthivel et al. 2002). The species has been extensively treated by Gams & Hawksworth (1975), Bridge et al. (1989) and Bills et al. (2004).

The isolates included in the present study exhibit the morphological features described for the species, which briefly consist of white to orange-white colonies on PDA at 25 °C, simple and branched conidiophores, cylindrical phialides of up to 60 μm long and cylindrical conidia, 4–7 × 1–2 μm arranged in slimy heads. Since no living culture of the type material of S. oryzae was preserved, we selected three isolates representative of the species to be included in the study i.e., CBS 180.74, considered an authentic strain of S. oryzae (Agnihothrudu 1974, Gams & Hawksworth 1975, Summerbell et al. 2011); CBS 399.73 extype strain of S. attenuatum, a synonym of S. oryzae (Bills et al. 2004), and an isolate of S. attenuatum (CBS 414.81) genetically different from the other two mentioned isolates (Bills et al. 2004). Our phylogenetic study showed that the three isolates had a similarity of 98.4–98.8 % with the three loci compared. In addition, the phenotypic characteristics observed were quite similar between them, which is why we preferred to maintain these isolates as a single species. Sarocladium oryzae is the type species of the genus and since living type material does not exist, we considered it important to design an epitype. The holotype of the species consists of a slide preserved in the Laboratory of Plant Pathology of the Taiwan National University. This material was studied and compared with CBS 180.74 by Gams & Hawksworth (1975) and Bridge et al. (1989). According to Gams, the structures observed in the type slide are identical to those observed in CBS 180.74. We agree that the morphological features of this strain fit with the protologue of S. oryzae (Gams & Hawksworth 1975), and hence we here designate it as epitype. The morphological differences between S. oryzae and the other species of the genus are summarised in Table 2.

Sarocladium pseudostrictum Giraldo, Gené & Deanna A. Sutton, sp. nov. — MycoBank MB807947; Fig. 5

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Fig. 5

Sarocladium pseudostrictum (sp. V) UTHSC 02–1892. a, b. Colonies on PDA after 14 d at 25 °C; c. acicular phialides arising laterally on the vegetative hyphae; d. conidia grouped in slimy heads; e. conidia. — Scale bars = 10 μm.

Etymology. Refers to the morphological similarity and the close phylogenetic relationship with Sarocladium strictum.

Colonies on OA at 25 °C attaining 20–31 mm diam in 14 d, yellowish white (1A2), flat, slightly powdery. On PDA at 25 °C reaching 19–23 mm diam in 14 d, orange white (6A2) to salmon (6A4), radially folded, membranous. Diffusible pigment absent. Vegetative hyphae septate, hyaline, smooth- and thin-walled, 1.5–2 μm wide. Conidiophores erect, simple, hyaline, smooth-walled. Phialides arising directly from vegetative hyphae, acicular, 20–47 μm long, 1–1.5 μm wide at the base, with a distinct periclinal thickening at the conidiogenous locus, thin- and smooth-walled, hyaline; adelophialides and schizophialides not observed. Conidia unicellular, ellipsoidal to cylindrical with rounded ends, occasionally slightly apiculate at the base, 3–5 × 1.5–2 μm, hyaline to subhyaline, smooth- and thin-walled, arranged in slimy heads. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth — Optimum 20–25 °C, maximum 30 °C, minimum 15 °C. No growth at 35 °C.

Specimen examined. USA, Wisconsin, from sputum, 2002, D.A. Sutton (holotype CBS H-21635, culture ex-type CBS 137660 = FMR 10347 = UTHSC 02-1892).

Notes — Sarocladium pseudostrictum nested together with S. strictum and S. bactrocephalum in a well-supported clade (BS = 99; PP = 1.00), which correlates with the morphological similarity of the three species; however, subtle differences among them can be observed. In contrast to S. pseudostrictum, S. strictum has a faster growth rate on PDA, larger phialides (up to 65 × 2.5 μm), the conidiophores are usually branched, produce adelophialides, and its conidia are longer (up to 7 μm). In contrast, S. bactrocephalum has a slower growth rate, white colonies on PDA, the conidia are narrower (0.5–1 μm), and the phialides shorter (up to 35 μm) than S. pseudostrictum.

Sarocladium subulatum Giraldo, Gené & Guarro, sp. nov. — MycoBank MB807948; Fig. 6

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Fig. 6

Sarocladium subulatum (sp. I) UTHSC 07–110. a, b. Colonies on PDA and OA, respectively, after 14 d at 25 °C; c, d. phialides arising directly from ropes of hyphae or on vegetative hyphae; e. phialide with periclinal thickening at the apex; f, g. conidia. — Scale bars = 10 μm.

Etymology. Refers to the phialide shape.

Colonies on OA at 25 °C attaining 26–30 mm diam in 14 d, yellowish white (4A2), flat with diffuse margin, powdery. On PDA at 25 °C reaching 17–20 mm diam in 14 d, yellowish white (4A2), flat, radially striated or crateriform with a lobulate margin, at first membranous becoming velvety. The isolate UTHSC 07-110 produces a diffusible deep yellow (4A8) pigment on PDA at 25 °C. Vegetative hyphae septate, hyaline, smooth- and thin-walled, 1.5–2 μm wide. Conidiophores erect, simple, hyaline, smooth. Phialides arising directly from vegetative hyphae or ropes of hyphae, straight or slightly flexuous, subulate, 14–24(–32) μm long, 2–2.5 μm wide at the base, with a distinct periclinal thickening at the conidiogenous locus, hyaline, thin- and smooth-walled; adelophialides sometimes present on OA, 8–12(–15) μm long, 1.5 μm wide at the base. Conidia unicellular, fusiform, 5–8(–9) × 1–2 μm, hyaline, thin- and smooth-walled, arranged in chains. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth — Optimum 20–25 °C, maximum 30 °C, minimum 15 °C. No growth at 35 °C.

Specimens examined. EGYPT, from soil, Apr. 1935, Sabet (holotype CBS H-21636), culture ex-type MUCL 9939 = CBS 217.35 = FMR 11044. – USA, California, from bone, July 2007, D.A. Sutton, CBS 137661 = FMR 10441 = UTHSC 07-110.

Notes — This species is closely related to S. bacillisporum and S. terricola. Sarocladium subulatum can be differentiated by its slower growth rate on OA and PDA at 25 °C, its inability to grow at 35 °C, and its conidial size (Table 2).

Sarocladium summerbellii Giraldo, Gené & Guarro, sp. nov. — MycoBank MB807949; Fig. 7

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Fig. 7

Sarocladium summerbellii (sp. IV). a, b, d–g. CBS 891.73; c, j–n. CBS 430.70; h, i. CBS 951.72. a. Colonies on PDA after 14 d at 25 °C; b, c. colonies on OA after 14 d at 25 °C; d, e. pigmented conidia collapsing in heads on PDA; f. phialide bearing conidia in chains; g. lateral and terminal phialides; h. phialide with distinct periclinal thickening at the apex (arrow); i. adelophialide; j. phialide with percurrently proliferation (arrow); k, m. fusiform conidia; l. conidia in different maturation phases; n. swollen conidia. — Scale bars: d, e = 20 μm; f–l = 10 μm; m, n = 5 μm.

Etymology. Named in honour of the eminent Canadian mycologist Richard Summerbell.

Colonies on OA at 25 °C attaining 26–30 mm diam in 14 d, waxy yellow (3B5), sunflower yellow (4C7–8), flat, powdery. On PDA at 25 °C reaching 15–21 mm diam in 14 d, pale yellow (4A3–4), light orange (5A4–5), crateriform, radially folded with a lobulate margin, velvety. Diffusible pigment absent. Vegetative hyphae septate, hyaline, smooth- and thin-walled, 1.5–2 μm wide. Conidiophores erect, usually simple, up to 42 μm long, straight or slightly bent, hyaline to subhyaline, smooth-walled. Phialides subulate, 15–40 μm long, 2–3.5 μm wide at the base, with a distinct periclinal thickening at the conidiogenous locus, thin- and smooth-walled, hyaline, sometimes with golden pigment accumulation at the base, often proliferating percurrently; adelophialides and schizophialides sometimes present. Conidia unicellular, fusiform with pointed ends, 3.5–8 × 1.5–2.5 μm, becoming limoniform to subglobose with age, up to 4 μm wide, hyaline, sometimes covered by a golden mucilaginous exudate, thin-walled, forming chains that soon collapse in slimy heads. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth —Optimum 20–25 °C, maximum 30 °C, minimum 15 °C. No growth at 35 °C.

Specimens examined. NETHERLANDS, Bleiswijk, isolated from soil of a greenhouse, Mar. 1970, G.J. Bollen (holotype CBS H-8266, culture ex-type CBS 430.70 = FMR 12318); from water in air moistener, June 1984, M.H.F. Luykx, CBS 200.84 = FMR 11761; Baarn, from decaying leaf of Canna indica, 1968, W. Gams, CBS 797.69 = FMR 12319; Wageningen, from agricultural soil, Nov. 1972, J.W. Veenbaas-Rijks, CBS 951.72 = FMR 12317. – SRI LANKA, Pidurutalagala, dead leaf, Jan. 1973, W. Gams, CBS 891.73 = FMR 12315.

Notes — All the isolates included in the A. summerbellii clade were originally identified as A. ochraceum. With the exception of CBS 891.73 that was collected in the tropics (Sri Lanka), the other isolates originate from temperate areas (viz. The Netherlands). Although the Dutch isolates clustered together into a well-supported subclade within the A. summerbellii clade, they are morphologically and genetically almost identical (> 99.8 % identity) to the Sri Lanka isolate. Sarocladium summerbellii differs from S. ochraceum by the presence of percurrently proliferating phialides producing conidia both in chains and slimy heads that are limoniform to subglobose with age, and its inability to grow at 35 °C.

Sarocladium terricola (J.H. Mill., Giddens & A.A. Foster) Giraldo, Gené & Guarro, comb. nov. — MycoBank MB807950

Basionym. Fusidium terricola J.H. Mill., Giddens & A.A. Foster, Mycologia 49: 796. 1957.

≡ Paecilomyces terricola (J.H. Mill., Giddens & A.A. Foster) Onions & G.L. Barron, Mycol. Pap. 107: 10. 1967.

≡ Acremonium terricola (J.H. Mill., Giddens & A.A. Foster) W. Gams, Cephalosporium-artige Schimmelpilze: 67. 1971.

≡ Sagrahamala terricola (J.H. Mill., Giddens & A.A. Foster) Subram. & Pushkaran, Kavaka 3: 89. 1975.

Colonies on OA at 25 °C attaining 44–50 mm in 14 d, white (1A1), flat, floccose, reverse light orange (5A4). On PDA at 25 °C attaining 24–37 mm in 14d, white (1A1), raised, radially folded, cottony, reverse light orange (5A4). Conidiophores erect, simple or poorly branched, hyaline to subhyaline, smooth-walled. Phialides subulate, 12–30(–35)μm long, 1–2 μm wide at the base, with distinct periclinal thickening at the conidiogenous locus, hyaline, thin- and smooth-walled;adelophialides and schizophialides sometimes present. Conidia unicellular fusiform with sharply pointed ends, 4–7(–8) × 1–2 μm, hyaline, smooth- and thin-walled, arranged in long dry chains. Chlamydospores and sexual morph not observed.

Cardinal temperature for growth —Optimum 20–25 °C, maximum 35 °C, minimum 15 °C. No growth at 37 °C.

Specimens examined. DEMOCRATIC REPUBLIC OF CONGO, Kinshasa, from decaying leaf of Milleta laurentii, Apr. 1967, G. Hennebert, FMR 11045 = MUCL 12011. – ITALY, Sardegnia, from Arundo donax, Aug. 1970, W. Gams, CBS 134.71 = FMR 11421. – MOROCCO, from infected palm grove, FSSM, FMR 11047 = MUCL 42865. – USA, Georgia, from mixed forest soil, May 1956, J.H. Miller (holotype J.H. Miller No. 1679, personal collection, culture ex-type CBS 243.59 = ATCC 13215 = FMR 10460 = IAM 14651 = IMI 100712 = MUCL 4112); Texas, from sputum, 2002, D.A. Sutton, FMR 10348 = UTHSC 02-1958; Michigan, from bronchial wash fluid, 2003, D.A. Sutton, FMR 10388 = UTHSC 03-2933; Minnesota, from sinus, 2004, D.A. Sutton, FMR 10561 = UTHSC 04-956; Illinois, from bone, 2007,D.A. Sutton, FMR 10450 = UTHSC 07-3260; Minnesota, from bronchial wash fluid, 2007, D.A. Sutton, FMR 10571 = UTHSC 07-3667; Texas, from bronchoalveolar lavage fluid, 2008, D.A. Sutton, FMR 10369 = UTHSC 08-3180; Texas, from bronchoalveolar lavage fluid, 2008, D.A. Sutton, FMR 10356 = UTHSC 08-844.

Notes —Sarocladium terricola is a species commonly found in soil and on plant material in tropical and subtropical countries (Onions & Barron 1967, Gams 1971). However, in our case, most of our strains are from clinical origin. Despite the fact that S. terricola has never been described as the etiological agent of any human disease, its repeated isolation from human samples, mainly from the respiratory tract, would suggest a possible pathogenic role.

This species nests in a well-supported clade together with S. bacillisporum and S. subulatum. These species are morphologically very similar, but can be differentiated in the following features: S. terricola has a fast growth rate on all the media tested and it is able to grow at 35 °C; S. bacillisporum produces small rod-shaped conidia (4–6 × 1 μm) and S. subulatum has large conidia (5–8(–9) × 1–2 μm) and its phialides are wider at the base (2–2.5 μm) than the other two species.