Appendices: Keys to Taxa

1.1 Appendix A: Key to Taxa Gigaspora Species Proposed by Gerdemann and Trappe in 1974

1a Azygospores hyaline to yellow or yellowish green, smooth 2 1b Azygospores light to dark brown 4 2a hyaline when fresh, with brown suspensor-like cells and G. gilmorei brown knobby, clustered -borne vesicles 2b Spores hyaline to yellow or greenish-yellow with concolorous 3 suspensor-like cells smooth to echinulate soil-borne vesicles 3a Globose spores less than 300 μm diam; vesicles smooth to knobby, G. formed singly calospora 3b Globose spores generally larger than 300 μm; vesicles echinulate G. gigantea formed in clusters 4a Globose spores larger than 300 μm, ornamented with scattered, G. irregularly shaped, hyaline warts and ridges 2 μm tall; vesicles coralloidea coralloid 4b Globose spores less than 300 μm, ornamented with minute spines; G. vesicles smooth (extra-limital species). heterograma

© Springer International Publishing Switzerland 2015 129 T. Souza, Handbook of Arbuscular Mycorrhizal Fungi, DOI 10.1007/978-3-319-24850-9 130 Appendices: Keys to Taxa Glomeromycota Species

1.2 Appendix B: Key to Taxa Family Endogonaceae Proposed by Tandy in 1975

Chlamydospores are subtended by one , and the and sporophore contents are directly connected or divided by a distinct septum. Zygospores are subtended by two hyphae and the endospore in continuous 1a Sporocarp containing zygospores 2 (Endogone spp.) 1b Sporocarp containing 6 (Glomus spp.) 2a Zygospores aggregated in distinct groups 3 2b Zygospores not aggregated, scattered throughout 5 fructifi cation 3a Zygospore wall in one thick (9–22 μm) layer Endogone crassa 3b Zygospore wall in two distinct layers, 25 μm together 4 4a Gametangia usually widely separated, discrete Endogone aggregata 4b Gametangia fused Endogone tuberculosa 5a Zygospore surrounded by a whorled sheath in surface Endogone view resembling a fi ngerprint fl ammicorona 5b Zygospore surrounded by a ramifying sheath, reticulate Endogone reticulata in surface view 6a with septum at its base Glomus pulvinatus 6b Chlamydospore without septum at its base 7 7a Chlamydospore mostly more than 130 μm in diameter Glomus macrocarpus var. macrocarpus 7b Chlamydospores less than 130 μm in diameter 8 8a Chlamydospore wall in one thick (3–4 μm) layer, Glomus tubiformis sporophore usually occlused 8b Chlamydospore wall in two layers, to 8 μm together, Glomus tener sporophore open

1.3 Appendix C: Key to Taxa Family Endogonaceae Proposed by Nicolson and Schenck in 1979

Key to Florida Endogonaceae 1a Forming chlamydospores free in the soil, in sporocarps or within 2 1b Forming azygospores on terminally swollen hyphae 3 2a Chlamydospores only in sporocarps containing a single tightly Sclerocystis packed layer of spores around a central plexus of hyphae 2b Chlamydospores usually free in soil or within roots; if in a Glomus sporocarp, not as in 2 above (continued) (continued) 3a Azygospores terminally attached to a swollen hyphal tip Gigaspora (suspensor-like cell) that frequently bears a smaller hypha projecting towards the spore; Spores usually free in soil with a bulbous (suspensor-like cell) attachment 3b Azygospores laterally attached to a swollen hypha tapering to a large terminal vesicle which collapses with age; spores usually free in the soil with no hyphal attachment Glomus 1a Chlamydospore walls on mature spores predominantly hyaline, 2 white or yellow occasionally becoming dark yellow to brown with age 1b Chlamydospore walls on mature spores predominantly brown to 5 black, occasionally yellow brown when young 2a Chlamydospore walls hyaline (becoming yellow with age), walls Glomus clarus 7–31 μm thick, frequently formed within the roots 2b Chlamydospore walls yellow to yellow brown, not formed within 3 the roots 3a Hyphal attachment to spore frequently funnel shaped, spores Glomus 100–300 μm in diam, spores formed ectocarpically or within mosseae sporocarps of 1–10 spores 3b Hyphal attachment not funnel shaped, spores usually less than 4 100 μm 4a Spores greater than 50 μm in diam, usually formed in sporocarps Glomus fulvus above the soil surface 4b Spores 50 μm in diam or less, hypogeous Glomus microcarpus 4c No spores usually formed, when present 10–12 μm in diam; Glomus tennis hyphae on roots thin (0.5–3.0 μm wide), with irregular swellings 5a Spores formed ectocarpically or in old roots, spore diam not 6 exceeding 150 μm 5b Spores not formed in old roots, spore diam frequently exceeding 7 150 μm 6a Young spores with an ephemeral outer wall up to 5 μm thick and a Glomus laminate inner wall 2–8 μm thick etunicatus 6b Spore without an ephemeral outer wall; spore wall yellow brown, Glomus 3–17 μm in diam; spores frequently tightly packed in sporocarps fasciculatus 7a Chlamydospores dark brown to black; not formed in sporocarps G. macrocarpus v. geosporus 7b Chlamydospores yellow brown; spores formed ectocarpically or in G. sporocarps macrocarpus v. macrocarpus Sclerocystis 1a Sporocarps enclosed in a peridium 2 1b Sporocarps not in a peridium; resembling a miniature blackberry Sclerocystis rubiformis 2a Sporocarp peridium composed of thick walled, sinuous hyphae Sclerocystis tightly enclosing the spores sinuosa 2b Sporocarp peridium without sinuous hyphae Sclerocystis coremioides (continued) 132 Appendices: Keys to Taxa Glomeromycota Species

(continued) Acaulospora 1a Azygospores over 100 μm in diam 2 1b Azygospores less than 100 μm in diam Acaulospora trappei 2a Azygospores with two readily separable walls; outer spore wall Acaulospora with cerebriforme folds up to 12 μm tall gerdemannii 2b Azygospores without readily separable walls, walls smooth Gigaspora 1a Azygospores light brown to dark brown or black 2 1b Azygospores hyaline, white, yellow or greenish yellow 5 2a Azygospores wall black, pitted with pores; spores over 250 μm Gigaspora diam; accessory vesicles in clusters nigra 2b Azygospores light to dark brown 3 3a Azygospores 250 μm or larger 4 3b Azygospores usually less than 250 μm; outer wall with minute Gigaspora spines; accessory vesicles in clusters heterograma 4a Accessory vesicles in clusters; outer wall continuous with Gigaspora irregular shaped projections 1–7 × 3–12 μm gregaria 4b Accessory vesicles borne singly, coralloid; wall surface with Gigaspora openly spaced hyaline ridges 2 μm tall by 0.5 6 μm broad (not coralloidea known to occur in Florida) 5a Azygospores with an outer wall readily separating under pressure 6 from the inner wall; azygospores hyaline 5b Azygospores without separable walls 7 6a Azygospores under 250 μm in diam; suspensor cell hyaline; Gigaspora accessory vesicles brown, knobby, borne singly or in clusters pellucida 6b Azygospores over 250 μm in diam; suspensor cell light brown; Gigaspora accessory vesicles pale brown, knobby, borne in clusters (not gilmorei known to occur in Florida) 7a Azygospore walls consisting of one layer, usually less than 5 μm Gigaspora thick; spores hyaline, white or shades of yellow; accessory calospora vesicles knobby, borne singly (not known to occur in Florida) 7b Azygospore walls consisting or more than one layer; accessory 8 vesicles borne in clusters 8a Azygospores predominantly some shade of yellow 9 8b Azygospores predominantly some shade of white 10 9a Azygospores yellow to greenish yellow; accessory vesicles spiny, Gigaspora borne in clusters; suspensor-like cell 41–51 μm in diam gigantea 9b Azygospores pale yellow to dull yellow, never turning greenish Gigaspora yellow; accessory vesicles in clusters, spiny to knobby; suspensor- aurigloba like cell 40–70 μm diam 10a Azygospores white to cream with a pink tint in the area of the Gigaspora suspensor-like cell; spores usually less than 300 μm in diam rosea 10b Azygospores white to cream; usually greater than 300 μm in diam Gigaspora margarita Appendices: Keys to Taxa Glomeromycota Species 133

1.4 Appendix D: Key to Taxa Family Endogonaceae Proposed by Hall and Fish in 1979

1a Sporocarps present, may be fused into mats; if few spores 2 in sporocarp (1–4) then peridium well-developed 1b Sporocarps absent but spores may be aggregated into loose 57 clusters 2a Spore sessile or spore attachments not seen (attachments 3 may be obscured by peridial hyphae) 2b Spore not as above 11 3a Spore wall single, or, if double, outer wall thin and diffi cult 4 to discern; if single may be laminate 3b Spore wall double or multiple 7 4a Sporocarp often exuding a sticky latex when cut; spores Glomus melanosporus containing a white latex; spore wall grading in colour from Gerdemann and Trappe dark at outer surface to subhyaline near inner surface 4b Sporocarp not exudes sticky latex when cut; spores not 5 containing White latex; spore wall uniform in colour 5a Spores in sporocarps arranged in single layer around a Sclerocystis sinuosa central plexus of sterile hyphae; peridium of tightly Gerdemann and Bakshi 5b Spores in sporocarps arranged randomly 6 6a Spores enclosed in tightly appressed hyphal mantles Glomus convolutus (cursory exanimation may suggest that the mantle is an Gerdemann and Trappe ornamentation of the spore wall); diam of sporocarps greater than 1 mm 6b Spores not enclosed in hyphal mantles; diam of sporocarps 21 less than 1 mm 7a Sporocarps often exuding sticky latex when cut; hyphal 46 mantle may be present 7b Sporocarps never exuding sticky latex when cut; Hyphal 8 mantle never present 8a Spores sessile or almost sessile, borne in a cluster on the Glomus fuegianus (Speg.) end of a swollen hyphal tip Trappe and Gerdemann 8b Spore not as above 9 9a Diam of sporocarps less than 1 mm but sporocarps may be 10 fused in pulvinata masses 9b Diam of sporocarps greater than 1 mm 48 10a Sporocarps containing many spores and whitish to light Endogone alba (Petch) grey (may be fused together in pulvinata masses) Gerdemann and Trappe 10b Sporocarps containing 1–12 spores and coloured but may 75 be pale if immature 11a Spore wall single, or, if double, outer wall thins and 12 diffi cult to discern; wall may be laminate 11b Spore wall double or multiple 36 12a Sporocarp with a covering of large thin-walled vesicles or 13 spores interspersed with large thin-walled vesicles (continued) 134 Appendices: Keys to Taxa Glomeromycota Species

(continued) 12b Sporocarp not as above 15 13a Spores in sporocarps arranged in a single layer around a Sclerocystis dussii (Pat.) central plexus of sterile hyphae; sporocarp diam less than Höhn. 1 mm; sporocarps fused to form a tuberculata crust on soil surface with the upper surface of the crust covered with thin-walled vesicles; fi sh-like odour when fresh, particularly if kept moist in a closed container 13b Spores in sporocarps arranged randomly or in discrete 14 clusters; sporocarp diam greater than 1 mm; sporocarps not fused but may form a crust on the soil surface; odour not distinctive 14a Spores in sporocarps may be arranged in clusters; pore Glomus vesiculifer partially occlused by wall thickening, never with a distinct (Thaxter) Gerdemann and septum; sporocarp with a well-developed peridium; spore Trappe length 150–230 μm 14b Spores in sporocarps arranged randomly; pore with a Glomus fl avisporus distinct septum, not occlused; sporocarp with a well- (Lange and Lund) developed peridium; spore length 150–230 μm Gerdemann and Trappe 15a Spores with thin walls and always containing few to many 16 thin-walled sporangiospores 15b Spore not as above but internal spores may be present in 17 some spores 16a Sporangia 55–118 μm diam, containing more than 20 Modicella malleola sporangiospores with 7–17 μm diam (Harkn.) Gerdemann and Trappe 16b Sporangia generally less than 60 μm diam, containing Modicella reniformis 4–12, rarely more, sporangiospores with 12–38 μm diam (Bres.) Gerdemann and Trappe 17a Spores clavate, much longer than broad, 140– Sclerocystis clavispora 185 × 20–50 μm, with a very thick-walled tip Trappe 17b Spore not as above 18 18a Outer surface of sporocarp a thick gelatinous wall. Glaziella aurantiaca Sporocarps hollow and bright orange, yellow or scarlet (Berk. and Curt.) Cke when fresh, up to 50 mm diam 18b Sporocarps not as above 19 19a Diam of sporocarps less than 1 mm (sporocarps may be 20 fused into pulvinata masses) 19b Diam of sporocarps greater than 1 mm 25 20a Spores in sporocarps arranged randomly; spores generally 21 globose, occasionally longer than broad 20b Spores in sporocarps arranged in a single layer around a 22 central plexus of sterile hyphae; spores often longer than broad (ellipsoid, ovoid, obovoid, or clavate) 21a Diam of spores 18–48 μm; sporocarps containing many Glomus pubescens (Sacc. spores; subtending hyphae inconspicuous, approximately and Ell.) Trappe and 2 μm diam Gerdemann 21b Diam of spores greater than 105 μm, sporocarps containing 75 1–12 spores; subtending hyphae greater than 8 μm diam (continued) Appendices: Keys to Taxa Glomeromycota Species 135

(continued) 22a Peridium containing scattered small globose Sclerocystis coccogena chlamydospores (Pat.) Höhn. 22b Peridium not as above or poorly-developed or absent 23 23a Pore usually with a distinct septum Sclerocystis coremioides Berk. and Br. 23b Pore never with a distinct septum 24 24a Peridium partially covering sporocarp or poorly developed Sclerocystis rubiformis or absent Gerdemann and Trappe 24b Peridium completely covering sporocarp, consisting of Sclerocystis sinuosa thick-walled sinuous hyphae completely enclosing Gerdemann and Trappe sporocarp 25a Spores with two subtending hyphae; spores in sporocarps Endogone crassa Tandy arranged in discrete clusters 25b Spores with one subtending hyphae; spores in sporocarps 26 random or arranged in radiate rows 26a Sporocarps often exuding a sticky latex when cut; spores Glomus melanosporus containing a white latex; spore wall grading in colour from Gerdemann and Trappe dark at outer surface to subhyaline near inner surface; subtending hyphae inconspicuous 26b Sporocarps not exuding a sticky latex when cut; spores not 27 containing a whit latex; spore wall uniform in colour 27a Spores in sporocarps produced acrogenously, arranged in Glomus radiatus radiate rows; Mature spore often fi lled with hyphae similar (Thaxter) Trappe and to the glebal hyphae Gerdemann 27b Spores in sporocarps random; mature spores rarely fi lled 28 with hyphae 28a Pore often with a distinct septum 29 28b Pore never with a septum 34 29a Sporocarps containing 1–2 spores Red-brown laminate (Mosse and Bowen) 29b Sporocarps containing many spores 30 30a Spores often longer than broad (ellipsoid, ovoid, or 31 obovoid) 30b Spore generally globose 33 31a Spore wall reddish-brown, up to 8 μm thick; sporocarps Glomus borealis naked, without a peridium (Thaxter) Trappe and Gerdemann 31b Spore wall hyaline to pale yellow, up to 4 μm thick; 32 sporocarps generally but not always with a peridium 32a Spores 55–160 μm in length; diam of subtending hypha at Glomus fulvus (Berk. and widest part 5–15 μm Br) Trappe and Gerdemann 32b Spores 70–100 μm in length; diam of subtending hyphae at Glomus canadensis widest part 4–6 μm (Thaxter) Trappe and Gerdemann 33a Pore not occluded and always with a distinct septum; Glomus pulvinatus spores 48–100 × 45–105 μm; wall becoming laminate with (Henn.) Trappe and age Gerdemann (continued) 136 Appendices: Keys to Taxa Glomeromycota Species

(continued) 33b Pore partially occlused with septum present in mature Glomus pallidus Hall spores; spores 32–78 × 28–68 μm; wall becoming laminate with age 34a Spores enclosed in tightly appressed hyphal mantles; Glomus convolutus spores containing a yellow oil Gerdemann and Trappe 34b Spores not enclosed in hyphal mantles; spores not 35 containing a yellow oil 35a Spores in sporocarps interspersed with trumpet-shaped Glomus tubiformis Tandy hyphae 35b Spores in sporocarps not interspersed with trumpet- shaped 70 hyphae 36a Spores with one subtending hypha 37 36b Spores with two subtending hyphae 45 37a Spore with a distinct septum 38 37b Pore never with a septum 40 38a Spore outer wall hyaline, 1–8 μm thick, extending up to Glomus caledonius 35 μm along subtending hypha as a loose sleeve (Nicol. and Gerd.) Gerdemann and Trappe 38b Spore outer wall hyaline, less than 1 μm thick, not 39 extending along subtending hypha 39a Sporocarps containing many spores; spores 49–73 μm Glomus fragilis (Berk. diam and Br.) Trappe and Gerdemann 39b Sporocarps containing 1–12 spores; spores 100–330 μm 75 diam 40a Spore wall multiple, consisting of 3–5 distinct layers Glomus gerdemannii Rose, Daniels and Trappe 40b Spore wall double 41 41a Sporocarps with a covering of large thin-walled vesicles or Glomus vesiculifer spores interspersed with large thin-walled vesicles (Thaxter) Gerdemann and Trappe 41b Sporocarp not as above 42 42a Spores sessile or almost sessile, borne in a cluster on the Glomus fuegianus (Speg.) end of a swollen hyphal tip; spores outer wall thicker than Trappe and Gerdemann inner wall 42b Spore not as above; spore outer wall much thinner than 43 inner wall 43a Outer surface of inner wall of mature spores ornamented Glomus monosporus with minute echinulate projections; projections and thin Gerdemann and Trappe outer wall may not be obvious on all spores; spores often fi lled with hyphae 43b Outer surface of inner wall not ornamented; spores rarely 44 fi lled with hyphae 44a Spore inner wall always hyaline; subtending hypha often Glomus tener Tandy constricted at point of attachment 44b Spore inner wall yellow to brown though may be hyaline 101 in young spores; subtending hyphae not constricted at point of attachment (continued) Appendices: Keys to Taxa Glomeromycota Species 137

(continued) 45a Sporocarps often exuding a sticky latex when cut 46 45b Sporocarps not exuding a sticky latex when cut 48 46a Spore outer wall generally slightly thicker than inner wall; Endogone oregonensis spores in sporocarps arranged in discrete clusters; spores Gerdemann and Trappe not enclosed in hyphal mantles 46b Spore outer wall much thinner than inner wall; spores in 47 sporocarps random; spores enclosed in tightly appressed hyphal mantles 47a Subtending hyphae persistent and up to 80 μm wide; Endogone lactifl ua Berk. hyphal mantle consisting of more than one layer of and Br. interwoven hyphae; width of spores 94–190 μm 47b Subtending hyphae less than 40 μm wide; subtending Endogone fl ammicorona hyphae generally disappearing by maturity; hyphal mantle Trappe and Gerdemann consisting of a single layer of spirally arranged hyphae; width of spores 42–99 μm 48a Spore outer wall much thinner than inner walls 49 48b Spore outer wall thicker than inner or walls of 52 approximately equal thickness 49a Sporocarps brick-red when fresh; spores enclosed in Endogone reticulata tightly appressed hyphal mantles; subtending hyphae Tandy generally persistent 49b Sporocarps orange to yellow when fresh; spores not 50 enclosed in hyphal mantles; subtending hyphae inconspicuous 50a Sporocarps often with a cavity opening to the exterior at Endogone pisiformis Lk maturity; spores in sporocarps random ex Fr. 50b Sporocarps without a cavity; spores arranged in discrete 51 clusters or radiate rows 51a Spores in sporocarps produced acrogenously in radiate Endogone acrogena rows; sporocarp surface covered at maturity by matted Gerdemann, Trappe and glebal hyphae (not a true peridium); sporocarps generally Hosford epigeous 51b Spores in sporocarps arranged in discrete clusters; Endogone verrucosa sporocarps surface naked; sporocarps generally hypogeous Gerdemann and Trappe 52a Spores in sporocarps random; sporocarps always globose Endogone incrassata to subglobose; sporocarps when fresh smelling of onions; Thaxter internal cavity present in mature sporocarps 52b Spores in sporocarps arranged in radiate rows and spores 53 produced acrogenously in discrete clusters, or in thin strata; sporocarps much lobed, irregular or variable; odour not distinctive; sporocarps without an internal cavity 53a Spores in sporocarps arranged in discrete clusters 54 53b Spores in sporocarps in radiate rows or smooth to 56 verrucose, folded and convoluted strata 54a Spores enclosed in tightly appressed hyphal mantles; Endogone multiplex sporocarps dirty whitish Thaxter 54b Spores not enclosed in hyphal mantles; sporocarps 55 yellowish but may be pale if immature (continued) 138 Appendices: Keys to Taxa Glomeromycota Species

(continued) 55a Spore outer wall much thicker than inner wall (4 μm and Endogone tuberculosa 1–2 μm thick respectively); spores 44–90 × 42–150 μm Lloyd 55b Spore walls approximately the same thickness (4–13 μm Endogone aggregata each); spores 78–103 × 118–182 μm Tandy 56a Spores in sporocarps arranged in smooth to verrucose Endogone stratosa folded strata, the spores within strata arranged randomly or Trappe, Gerdemann and in discrete clusters; spores enclosed in tightly appressed Fogel hyphal mantles; spores 113–177 × 82–149 μm 56b Spores in sporocarps produced acrogenously, arranged in Endogone acrogena radiate rows; spores not enclosed in hyphal mantles; spores Gerdemann, Trappe and 15 × 30–80 × 59 μm; subtending hyphae often disappearing Hosford by maturity 57a Spore surface covered in projections 4–30 × 2–5 μm, often 58 with the tips refl exed 57b Spore surface not as above 60 58a Spores and subtending hyphae light to dark brown; Crenulate spore (Hall; subtending hyphae with 2–5 distinct septa Mosse and Bowen) 58b Spores and subtending hyphae hyaline; subtending hyphae 59 without septa, fragile and often disappearing by maturity 59a Projections on spore surface 12–30 μm high White reticulate spore (Hayman)

59b Projections on spore surface less than 6 μm high WUM4 60a Spore wall single, or, if double, outer thin and diffi cult to 61 discern. If wall single may be laminate 60b Spore wall double or multiple 76 61a Diam of spores less than 15 μm, associated with vesicular Glomus tenuis (Geenall) arbuscular with hyphae rarely exceeding 2 μm Hall diam and with vesicles less than 15 μm diam 61b Diam of spores greater than 15 μm and if associated with 62 vesicular arbuscular mycorrhizas then with hyphae and vesicles not as above 62a Spores with 1–4 subtending hyphae, generally attached at Glomus multicaulis opposite ends of spores; spore wall thick (8–34 μm) with Gerdemann and Bakshi rounded projections 1.2–3.7 μm high and regularly distributed over spore surface 62b Spore attachment generally single or spore sessile; spore 63 wall not ornamented 63a Spore sessile, borne laterally on a thin-walled hypha Acaulospora trappei ending in thin-walled mother spore; spores Ames and Lindermann 50–82 × 42–72 μm, always hyaline 63b Spore not sessile; if subtending hyphae not seen spores 64 generally generate than 100 μm diam; spores hyaline or coloured

64a Subtending hypha with a single lateral projections; spores WUM8 always hyaline; spore wall approximately 4 μm thick; subtending hyphae may be inconspicuous 64b Subtending hypha lacking a lateral projection; spores 65 hyaline or coloured; subtending hyphae generally persistent and conspicuous (continued) Appendices: Keys to Taxa Glomeromycota Species 139

(continued) 65a Subtending hypha simple; spores hyaline or coloured 66 65b Subtending hypha funnel-shaped; spores and subtending 74 hyphae coloured 66a Subtending hypha constricted at point of attachment to Glomus constrictum spore and with many attached fi ne hyphae; pore never with Trappe a septum 66b Subtending hypha not constricted at point of attachment 67 and generally without fi ne hyphae attached; pore may have a septum; 67a Spore surface ornamented with minute echinulations, a Glomus monosporus thin outer wall should be present on some spores; spores Gerdemann and Trappe often fi lled with hyphae at maturity 67b Spore surface not ornamented; spores rarely fi lled with 68 hyphae 68a Pore often with a distinct septum 69 68b Pore never with a septum 70 69a Spores 32–78 × 28–68 μm, white to pale yellow Glomus pallidus Hall 69b Spores greater than 68 μm wide, yellow, brown or reddish 119 brown 70a Width of spores 25–35 μm but generally less than 50 μm; Glomus microcarpus Tul. spore wall up to 7 μm thick and Tul. 70b Width of spores 35–400 μm but generally greater than 71 50 μm; spore wall up to 17 μm thick 71a Spores dark brown to black; subtending hypha yellow to Glomus macrocarpum dark brown with wall thickenings extending 50–150 μm var. geosporus (Nicol. along hypha; spores always ectocarpic and Gerd.) Gerdemann and Trappe 71b Spores hyaline, yellow, brown, or reddish-brown; 72 subtending hypha not as above; spores ectocarpic or sporocarpic 72a Width of spores 35–105 μm Glomus fasciculatus (Thaxter sensu Gerdemann) Gerdemann and Trappe 72b Width of spores 95–400 μm 73 73a Spore reddish-brown; spore wall always laminate; thin Red-brown laminate outer wall never present; sporocarps if present containing (Mosse and Bowen) 1–2 spores 73b Spores hyaline, yellow or brown; spore wall may be Glomus macrocarpus var laminate; spores with thick-walled subtending hyphae may macrocarpus Tul. and have a thin outer wall; sporocarps if present. Containing Tul. many spores

74a Pore never with a distinct septum WUM2 74b Pore often with a distinct septum 75 75a Spores often fi lled with hyphae; sporocarp containing 1–3 Glomus monosporus spores; diam of subtending hyphae at widest part 8–26 μm; Gerdemann and Trappe outer surface of inner wall of mature spore ornamented with minute echinulate projections; projections and thin outer wall may not be obvious on all spores (continued) 140 Appendices: Keys to Taxa Glomeromycota Species

(continued) 75b Spores rarely fi lled with hyphae; sporocarp containing Glomus mosseae (Nicol. 1–10 spores; diam of subtending hyphae at widest part and Gerd.) Gerdemann 18–50 μm; outer surface of inner wall not ornamented; thin and Trappe hyaline outer wall may no be obvious on all spores 76a Double spore wall 77 76b Spore wall multiple consisting of 3 or more distinct layers 103 77a Spores hyaline to white at maturity 78 77b Spores coloured though may be pale when young 82 78a Subtending hypha bulbous, often with one or more lateral 79 projections; soil-borne vesicles may be present 78b Subtending hypha simple or funnel-shaped or not seen; 81 soil-borne vesicles never present 79a Spore wall consisting of 2–5 layers, each layer 1–2 μm Gigaspora rosea thick; portion of spore wall around subtending hypha with Nicolson and Schenck a distinct to barely detectable rose-pink tint 79b Spore wall always double; spore wall never with a 80 rose-pink tint

80a Warts formed on inner wall surrounding the bases of the WUM7 germ tubes; germ tube not arising from compartments in the spore wall; spores globose to subglobose 80b Warts not formed during germination; germ tubes arising Type 3 (Sward et al.) from compartments in spore wall; spores generally broader than long

81a Subtending hypha funnel-shaped and fragile; spore outer WUM3 wall thinner than inner walls of approximately the same thickness; walls readily separable; outer surface of inner wall with smooth to irregular bumps and hollows up to 1 μm high with the inner surface of the outer wall matching

81b Subtending hypha simple and generally persistent; spore WUM5 outer wall thicker than inner wall; walls not readily separable; outer surface of inner wall not ornamented 82a Spore surface ornamented with warts and ridges, minute 83 spines, or cerebriforme folds 82b Spore surface not ornamented 85 83a Spores sessile, borne laterally on a thin-walled hypha Acaulospora gerdemannii ending in a thin-walled mother spore; parent hypha often Schenck and Nicolson not seen; soil-borne vesicles never present; spore surface ornamented with cerebriforme folds up to 10–12 μm high 83b Spores not sessile; subtending hypha bulbous and 84 persistent; soil-borne vesicles may be present; spore surface ornamented with warts and ridges or minute spines 84a Spore surface ornamented with scattered irregularly shaped Gigaspora coralloidea warts and ridges about a 2 μm high; diam of spores greater Trappe, Gerdemann and than 300 μm; soil-borne vesicles if present, coralloid and Ho borne singly 84b Spore surface ornamented with minute spines; diam of Gigaspora heterograma spores less than 300 μm; soil-borne vesicles, if present, (Nicol. and Gerd.) smooth and borne in clusters of 1–10 Gerdemann and Trappe (continued) Appendices: Keys to Taxa Glomeromycota Species 141

(continued) 85a Ornamentation of outer surface of inner wall generally 86 present in mature spores (polygonal projections, small echinulations, or irregular) 85b Ornamentation of outer surface of inner wall not occurring 88 or not a regular feature 86a Spore outer wall much thinner than inner wall; outer Glomus monosporus surface of inner wall ornamented with minute Gerdemann and Trappe echinulations 86b Spore outer wall thicker than inner wall or walls of equal 87 thickness; outer surface of inner wall ornamented with polygonal projections or irregular

87a Spore walls of equal thickness; outer surface of inner wall WUM1 irregular; spore develops terminally on a simple hypha 87b Spore outer wall thicker than inner wall; outer surface of infrequens inner wall ornamented with polygonal projections; spore (Hall) Ames and develops in a hyaline hypha which subtends a hyaline Schneider vesicle. Spore thus with a smooth hyaline outer wall and a brown, ornamented inner wall. A stalk continuous with the inner spore wall joins the contents of the spore and those of the vesicle 88a Spores sessile or almost sessile borne in a cluster on the Glomus fuegianus (Speg.) end of a swollen hyphal tip Gerdemann and Trappe 88b Spores not as above 89 89a Subtending hypha bulbous; soil-borne vesicles may be 90 present 89b Subtending hypha simple or funnel-shaped; spol borne 94 vesicles never present 90a Portion of spore wall surrounding subtending hypha with a Gigaspora rosea distinct to barely detectable rose-pink tint; spores whitish Nicolson and Schenck to cream 90b Spore wall surrounding subtending hypha without a 91 rose-pink tint; spores yellowish or greenish 91a Spore outer wall much thinner than inner wall; soil-borne Gigaspora gigantea vesicles, if present, with septate echinulations at apex (Nicol. and Gerd.) Gerdemann and Trappe 91b Spore outer wall much thicker than inner wall or walls of 92 approximately equal thickness; soil-borne vesicles if present, smooth to echinulate to knobby

92a Spore walls of approximately equal thickness, outer brittle, WUM6 inner fl exible each of a layers which are not always obvious 92b Spore outer wall much thicker than inner wall 93 93a Mature spores pale yellow to pale greenish yellow; Gigaspora calospora soil-borne vesicles, if present, 23–33 μm diam, smooth to (Nicol. and Gerd.) knooby, borne singly; germ tubes arising directly through Gerdemann and Trappe the spore wall (continued) 142 Appendices: Keys to Taxa Glomeromycota Species

(continued) 93b Mature spores bright Golden yellow, becoming dull yellow Gigaspora aurigloba Hall with age and brown when moribund; soil-borne vesicles, if present, up to 100 μm diam, echinulate to knooby to polymorphic, borne in loose clusters; germ tubes arising from compartments in spore wall 94a Pore usually with a distinct septum 95 94b Pore never with a distinct septum 98 95a Spore outer wall honey brown, thicker than hyaline inner Type 8 (Sward et al.) wall 96a Spore outer wall 1–8 μm thick, extending up to 35 μm 120 along subtending hypha 96b Spore outer wall less than 1 μm thick, not extending along 97 subtending hypha 97a Spores 49–73 μm diam; diam of subtending hypha at Glomus fragilis (Berk. widest part 6–13 μm and Br.) Trappe and Gerdemann 97b Spores 105–310 μm diam; diam of subtending hypha at Glomus mosseae (Nicol. widest part 20–50 μm and Gerd.) Gerdemann and Trappe 98a Spore outer wall extending up to 100 μm along subtending Glomus invermaius Hall hypha as a tightly sleeve; spores 50 75 wide 98b Spore outer wall not extending along subtending hypha; 99 spores greater than 93 μm in width 99a Subtending hypha simple, may be constricted 100 99b Subtending hypha funnel-shaped 102 100a Subtending hypha constricted at the point of attachment Glomus constrictus and with fi ne hyphae attached Trappe 100b Subtending hypha not constricted at the point of 101 attachment and generally without attached fi ne hyphae 101a Spores bright yellow to bright brownish yellow, Glomus epigaeus Daniels 95–104 μm wide; diam of subtending hypha at the widest and Trappe part usually less than 10 μm; subtending hypha often inserted into the spore wall; pore at point of attachment of subtending hypha occluded by a septum-like plug; spores borne singly, in loose clusters, or in epigeous sporocarps 101b Spore yellowish brown to dark brown, 95–400 μm wide; Glomus macrocarpus var. diam of subtending hypha at widest part usually greater macrocarpus Tul and Tul. than 10 μm; subtending hypha not inserted; pore without a plug but may be occluded by wall of subtending hypha; spores borne singly, in loose clusters, or in generally hypogeous sporocarps 102a Spore outer wall 9–20 μm thick, inner wall up to 4 μm Glomus magnicaulis Hall thick; subtending hypha with a sing wall

102b Spore walls of approximately the same thickness (total WUM2 3–6 μm); subtending hypha with a distinctly double wall 103a Spores creamy white; walls a total of (25)–45–45 μm Type 7 (Sward et al.) thick; outer wall rough; subtending hypha simple, generally disappearing by maturity (continued) Appendices: Keys to Taxa Glomeromycota Species 143

(continued) 104a Spore sessile, borne laterally on a thin-walled hypha 105 ending in a thin-walled mother spore; parent hypha often not seen; soil-borne vesicles never present 104b Spore not sessile; subtending hypha obvious, either simple, 108 funnel-shaped, or bulbous; soil-borne vesicles may be present 105a Spore surface distinctly ornamented with regular pits, 106 spines or ridges 105b Spore surface generally not ornamented but may appear 107 minutely perforate at maturity 106a Spore surface evenly covered with pits 1–1.5 × 1–3 μm separated by ridges 2–4 μm thick; spores subhyaline to Trappe pale green to light brown 106b Spore surface covered by a distinct reticulum with small spines within the spaces of the reticulum; spores yellow to Trappe and Gerdemann brown 107a Spores deep red to reddish-brown, 288–800 μm diam Acaulospora large red species (Hall) 107b Spores pale yellow, pink, yellow brown, red brown or olive Acaulospora laevis brown, 119–520 μm diam. Wall minutely perforate in older Gerdemann and Trappe spores with the outer surface sloughing off 108a Spores hyaline to white at maturity, but portion of spore 109 wall surrounding the subtending hypha may have a rose-pink tint 108b Spore coloured though may be hyaline when young 113 109a Subtending hypha simple or funnel-shaped, without lateral Glomus clarus Nicolson projections; wall of subtending hypha from 7–39 μm thick and Schenck extending up to 400 μm below the spore 109b Subtending hypha bulbous, sometimes with a single lateral 110 projection 110a Spore wall consisting of 2–10 layers each layer 1–4 μm 111 thick 110b Spore wall consisting of 3–5 layers of unequal thickness; 112 outer two layers brittle, readily separable from 1 to 3 fl exible inner layers 111a Spore wall consisting of 4–10 layers, each layer 1.5–4 μm Gigaspora margarita thick; spores always hyaline to white Becker and Hall 111b Spore wall consisting of 2–5 layers, each layer 1–2 μm Gigaspora rosea thick; portion of spore wall surrounding subtending hypha Nicolson and Schenck with a distinct to barely detectable rose-pink tint 112a Spores generally greater than 200 μm in length Gigaspora gilmorei Trappe and Gerdemann 112b Spores generally less than 200 μm in length Gigaspora pellucida Nicolson and Schenck 113a Subtending hypha bulbous, sometimes with a single lateral 114 projection; soil-borne vesicles may be present 113b Subtending hypha simple, without a lateral projection; soil 118 borne vesicles never present (continued) 144 Appendices: Keys to Taxa Glomeromycota Species

(continued) 114a Spore surface ornamented with pores or irregular 115 projections 114b Spore surface not ornamented 116 115a Spore surface ornamented with large pores 7–10 μm diam Gigaspora nigra Redhead with smaller pores within them 115b Spore surface ornamented with irregular projections Gigaspora gregaria 1–7 × 3–12 μm Schenck and Nicolson 116a Spore wall of three layers, outer up to 15 μm thick, inner Type 4 (Sward et al.) up to 20 μm, middle up to 2 μm thick 116b Spore outer wall much thicker than inner walls, or wall of 117 approximately equal thickness 117a Spore outer wall 6–16 μm thick; 1–3 hyaline inner wall Gigaspora aurigloba Hall each approximately 1 μm thick

117b Spore wall of two layers of approximately equal thickness, WUM6 outer brittle, inner fl exible, each of two layers of approximately equal thickness 118a Spore wall 5–16 μm thick, consisting of many layers each Glomus laminated spores approximately 1 μm thick var. macrocarpus (Hall) 118b Spore wall 5–13 μm thick, in mature spores consisting of Glomus gerdemannii three thin layers enclosed in the rough amorphous Rose, Daniels and Trappe remnants of the degenerating outer wall 119a Spores reddish-brown; outer wall never present Red-brown laminate (Mosse and Bowen) 119b Spores yellow to brown; ephemeral hyaline outer wall Glomus etunicatus intact only on immature spores Becker and Gerdemann 120a Outer wall ephemeral, rarely intact on mature spores Glomus etunicatus Becker and Gerdemann 120b Outer wall usually persistent Glomus caledonius (Nicol. and Gerd.) Gerdemann and Trappe

1.5 Appendix E: Key to Taxa Acaulospora Species Proposed by Walker and Trappe in 1981

1a Spores less than 100 μm broad, hyaline to very pale yellow; wall Acaulospora apparently single, roughened so minutely as to appear smooth trappei 1b Spores broader than 100 μm, hyaline to olive, brown, or dark reddish 2 brown; wall with two or more layers; surface shiny-smooth or distinctly ornamented 2a Spores shiny-smooth, globose to ellipsoid or reniform, 119–300 × 119– Acaulospora 520 μm, olive to yellowish brown or reddish brown; wall with a rigid laevis outer layer 2–4 μm thick and two thin inner layers 2b Spores distinctly ornamented 3 (continued) Appendices: Keys to Taxa Glomeromycota Species 145

(continued) 3a Spores with spines or polygonal projections, with or without a reticulum 4 3b Spores with pits or cerebriforme folds, lacking a surface reticulum 6 4a Reticulum lacking; spores with crowded spines 0.5–2 μm tall, sometimes Acaulospora overlaid with irregular, patchy hyaline encrustations spinosa 4b Reticulum present; spores surface between reticulum walls with crowded 5 spines or polygonal projections 5a Spore surface with crowded spines 2 × 0.5 μm, with a hyaline, alveolate Acaulospora reticulum overlaid on the spines at maturity; reticulum wall 1—layered, elegans 1 μm thick; spores globose to ellipsoid, 140–285 × 145–330 μm, olive to brown or reddish brown 5b Spore surface with polygonal projection 1 × 1 μm, enclosed by a grayish Acaulospora green, alveolate reticulum with 3—layered walls 1.5–2 μm broad; spores bireticulata globose, 150–155 μm in diam, light brown 6a Spore surface with cerebriforme folds up to 12 μm tall; spores globose, Acaulospora 200–250 μm in diam, brown; walls 2—layered, the inner layer reticulate gerdemannii 6b Spore surface pitted 7 7a Spores white to light olive brown, 100–240 × 100–220 μm, the surface Acaulospora with pits 1–1.5 × 1–3 μm separated 2–4 μm scrobiculata 7b Spores dark reddish brown to nearly black, 200–260 × 220–260 μm, the Acaulospora surface with pits 4–8 × 4–16 μm irregularly separated by 1–12 μm foveolata

1.6 Appendix F: Key to Taxa Gigaspora Species Proposed by Koske and Walker in 1985

1a Outer wall with low warts and with blunt projections 4–10 μm long Gigaspora dipapillosa 1b Outer wall with warts or patches, not with long, blunt projections 2 2a Warts widely scattered, patch-like, fl attened, with angular to Gigaspora subangular margins coralloidea 2b Warts crowded, mostly rounded or conical, occasionally irregular 3 3a Inner wall group hyaline to pale yellow, 0.5–3 μm thick, composed Gigaspora of two apparently fused membranous walls when viewed in optical heterograma sections; warts mostly 0.5–1 μm diam 3b Inner wall group of a single hyaline to pale yellow membranous wall 4 0.5–1 μm thick; warts as above or larger 4a Warts 2–10 μm diam (ca. 4 μm average), brown, very conspicuous; Gigaspora spores dark brown or dark red-brown gregaria 4b Warts mostly less than 5 μm diam (average <2 μm); spores hyaline 5 to brownish-orange 5a Warts mostly 0.5–1.5 (–3) μm diam, readily observable at 400× Gigaspora verrucosa 5b Warts almost all smaller than 1 μm diam, mostly about 0.5 μm, Gigaspora indistinct at 400× persica (continued) 146 Appendices: Keys to Taxa Glomeromycota Species

1.7 Appendix G: Key to Taxa Glomus Species Proposed by McGee in 1986

1a Spores in sporocarp mostly 10–80 μm diam 2 1b Spores in sporocarp mostly 70–350 μm diam 5 2a Spores mostly with septum when mature 3 2b Spores without septum 4 3a Spores with one wall Glomus arborense 3b Spores with more than one wall Glomus cerebriforme 4a Forms ectomycorrhizae, spores 10–40 μm diam Glomus tubiforme 4b Forms VA mycorrhizae, spores 20–60 μm diam Glomus microcarpum 5a Mucilage over all structure 6 5b No mucilage 7 6a Forms epigeous sporocarps, spores in sporocarps mostly Glomus 200–300 μm warcuppi 6b Forms hypogeous sporocarps, spores in sporocarps mostly Glomus 80–150 μm clarum 7a Subtending hyphae 15–35 μm 8 7b Subtending hyphae 4–9 μm, spores yellow to orange Glomus tenerum 8a Sporocarps fi rm, rounded, with peridium, spores with fi ne outer Glomus wall, thicker inner wall caledonium 8b Sporocarps fragile, open, lacking peridium, spores with two walls of Glomus similar thickness macrocarpum

1.8 Appendix H: Key to Taxa Proposed by Morton and Benny in 1990

1a Only arbuscules formed in mycorrhizal roots; Azygospores Gigasporineae (2) produces on the apex of a sporogenous cell of a fertile hypha; Auxiliary cells formed 1b Arbuscules and vesicles formed in mycorrhizal roots; Glomineae (3) Chlamydospores produces terminally or laterally on or within fertile hyphae; Auxiliary cells not produced 2 With a single family (4) 3a Chlamydospores formed apically from fertile hyphae Glomaceae (5) (continued) Appendices: Keys to Taxa Glomeromycota Species 147

(continued) 3b Chlamydospores formed from or within the “neck” of a sporiferous saccule (6) 4a Germ tubes produces directly through spore wall; Inner fl exible Gigaspora wall group absent; Auxiliary cells fi nely papillate or echinulate 4b Germ tubes from germination shield; Inner fl exible wall group Scutellospora always present; Auxiliary cells knobby, broadly papillate, or smooth 5a Fruiting body of a sporocarp composed of spores will lateral walls Sclerocystis adherent to one another; Connecting hyphae embedded in a central hyphal plexus; Chlamydospores in a single layer except at the base; Base composed of sterile hyphae 5b Fruiting structure a sporocarp not formed as in “D” above; Spores Glomus also produced singly or in loose to tight aggregates in soil; Less commonly in roots 6a Spores arise laterally from the neck of a sporiferous saccule Acaulospora 6b Spores formed in the neck of the sporiferous saccule Entrophospora

1.9 Appendix I: Key to Taxa Pacispora Species Proposed by Oehl and Sieverding in 2004

1a Spores generally with smooth surface 2 1b Spores with ornamented surface 3 2a Spore generally hyaline to subhyaline Pacispora franciscana 2b Spores rusty brown in colour Pacispora robigina 3a Spores with tubes, warts or knobs on the outer spore 4 wall layer 3b Spores with pits on the second layer of the outer wall Pacispora boliviana 4a Tiny tuber longer than 5 μm, generally 4–5 times Pacispora chimonobambusae longer than broad 4b Fine tuber (0.5–1.2 μm in diam) shorter than 5 μm, Pacispora dominikii usually 1.2–3 times longer than broad, spores generally <175 μm in diam 4c Knobs with length and width usually equal (1–3 μm), Pacispora scintillans spores generally >175 μm in diam, outer wall generally <5 μm thick 4d Warts with length and width usually equal (3–5 μm) Pacispora coralloidea or broader than high; spores generally <165 μm in diam; outer wall generally >5 μm thick 148 Appendices: Keys to Taxa Glomeromycota Species

1.10 Appendix J: Key to Taxa Acaulospora Species Proposed by Oehl and Co-workers in 2006

1a Spores with spines or polygonal projections with or without a 2 reticulum 1b Spores with depressions (pits) or cerebriforme folds 6 2a Spore spines or projections with a reticulum 3 2b Spore spines or projections without a reticulum 4 3a Reticulum three-layered enclosing polygonal projections Acaulospora 1 × 1 μm; spores generally 150–200 μm bireticulata 3b Reticulum one-layered, overlaid over crowded, densely- Acaulospora organized spines 2 μm high; spores 140–280 μm elegans 4a Spores with fi ne spines or tubercles 5 4b Spores with circular to oblong projections, 4–5 (–9) μm wide Acaulospora and up to 3.2 μm high; each projection with a center cavity denticulata 5a Spores with fi ne crowded, densely organized spines, 1–4 μm tall, Acaulospora 1 μm at base and tapering to 0.5 at the tip spinosa 5b Spores with fi ne tubercles 0.7–3.5 μm long and 1.5 μm broad at Acaulospora the base, tapering to 0.7–1.1 at the rounded tip, irregular tuberculata distances (0.5–3 μm) between single tubercles 6a Spores with pits 7 6b Spores with cerebriforme folds 7a Spores in sporocarps, spores 75–80 μm diam, ornamentation of Acaulospora 0.5–1 μm wide, 4–5 side pits, 1.2 × 0.5–1 μm across, ridges from taiwania mesh 7b Spores formed singly in soil, not in sporocarps 8 8a Pits of irregular shape 9 8b Pits of regular round shape 10 9a Spores 100–240 μm diam, subhyaline to light olive, circular to Acaulospora ellipsoid to y-shaped pits, 1.0–1.5 × 1.0–3 μm diam scrobiculata 9b Spores 100–180 μm diam reddish-yellow to yellow-brown, with Acaulospora irregular, saucer-shaped pits, 0.2–3 × 0.2–6 μm diam lacunosa 10a Spores with regular round pits, spores regularly <100 μm diam 11 10b Spores with regular round pits, spores regularly >100 μm diam 12 11a Spores hyaline to subhyaline 13 11b Spores yellow to orange brown, truncated cone shape pits of Acaulospora widest diameter of 1.5–2.2 μm alpina 12a Spores regularly 100–180 μm diam 14 12b Spores regularly >185 μm diam with concave round pits of Acaulospora widest diameter 4–10 μm foveata 13a Spores hyaline to subhyaline, concave round pits of widest Acaulospora diameter <3.5 μm paulinae 13b Spores hyaline to subhyaline, concave round pits of widest Acaulospora diameter >3.5 μm undulata 14a Spores yellow brown, 115–170 μm diam with concave round pits Acaulospora of widest diameter 2–5 μm cavernata 14b Spores ochre to brown, 100–180 (–200) μm diameter with Acaulospora concave round pits of widest diameter 4–20 μm excavata Appendices: Keys to Taxa Glomeromycota Species 149

1.11 Appendix K: Key to Taxa Order Proposed by Oehl and Co-workers in 2008

1a Spores with one spore wall; generally with germ warts on inner Family 1: surface of the wall in mature spores Gigasporaceae ( Gigaspora ) 1b Spores with outer spore wall and one to three inner walls; 2 germination shield on innermost wall 2a Spores with a hyaline to subhyaline seldom light yellow 3 germination shield 2b Spores with a yellow brown to brown germination wall Family 4: Dentiscutataceae (3 genera) 4 3a Germ shield simples, generally bi-lobed, (but sometimes Family 2: mono-lobed) thus (1–) 2 germ tube initiations (gtl); spores with Scutellosporaceae three walls ( Scutellospora ) 3b Germ shield multiple-lobed, four or more compartments with Family 3: each one gtl Racocetraceae (2 genera) 5 4a Germination shield simple, generally bi-lobed; spores with three Fuscutata walls 4b Germination shield complex, >8 compartments, each with a gtl; 6 shield periphery generally dentate in planar view; spores with three or more wall 5a Spores with two walls Racocetra 5b Spore with three walls Cetraspora 6a Spore with three walls Dentiscutata 6b Spores with >3 walls Quatunica Gigaspora 1a Mean diameter of mature spores <250 μm; spores rarely 2 >300 μm 1b Mean diameter of mature spores >250 μm; spores generally 3 >300 μm 2a Spores white when young 4 2b Spores white to cream, usually with a rose-pink tint; 230– Gigaspora rosea 300 μm in diam; sporogenous hyphae darker than the spore wall color 3a Spores pearly white when young, 200–490 μm in diam 5 3b Spores generally pigmented already when young; 290–810 μm Gigaspora in diam; mature spores brilliant yellow-green, color associated gigantea with spore contents; spore contents turning bright red in alkaline solutions; laminae of spore wall not turning dark purple in Melzer’s reagent; composite wall thickness generally <10 μm 4a Mature spores dull white with sporogenous hyphae similar in 6 color with spore wall 4b Spores (orange) white to white orange, 140–270 μm in diam Gigaspora alboaurantiaca (continued) 150 Appendices: Keys to Taxa Glomeromycota Species

(continued) 5a Spores with one sporogenous hyphae, 260–480 μm in diam Gigaspora mature spores pearly white to an opaque, creamy yellow color; margarita composite wall thickness generally <25 μm in diam 5b Spores with composite spore wall thickness generally >25 μm, 7 200–500 μm in diam; mature spores yellow to brown 6a Spores with composite spore wall thickness generally <8 μm, Gigaspora 200–300 μm in diam, average 250 μm, sporogenous cell dull candida white 30–50 μm diam 6b Spore with composite spore wall thickness <12 μm, 143–350 μm Gigaspora albida in diam, average 265 μm, sporogenous cell hyaline to yellow 24–50 μm in diam, average 265 μm, sporogenous cell hyaline to yellow 24–50 μm diam 7a Spores with composite spore wall thickness generally >25 μm, Gigaspora 320–490 μm in diam; mature spores golden yellow to brown, decipiens with one sporogenous cell 7b Spores as in 6a, subtending hypha forms one or more Gigaspora sporogenous cells one on top of other appearing as beads, spores ramisporophora formed on last cell; from any of the sporogenous cell another subtending hypha can emerge and may or may not form another sporogenous cell from which another spore forms Scutellospora 1a Spores without ornamentation on outer wall 2 1b Spores with ornamentation on outer wall 3 2a Spores light colored; subhyaline, pink, creamy, straw to greenish 4 or brownish yellow 2b Spores yellow brown to black 5 3a Spores with one homogenous ornamentation on spore surface 6 3b Spores with two-type ornamentation on spore surface 7 4a Spores subhyaline to creamy to pale straw to greenish yellow 8 4b Spores dark yellow to golden yellow to brown yellow 9 5a Spores yellow brown to orange-brown, 160–360 μm in diam, Scutellospora outer and innermost wall strongly staining in Melzer’s reagent arenicola 5b Spores dark brown to black, 300–460 μm in diam Scutellospora tricalypta 6a Spores hyaline to pale yellow, 160–270 μm in diam; with knobs Scutellospora 3.5–6.5 μm high and 7.0–10.5 μm wide at base nodosa 6b Spores golden yellow to ochraeous to sienna, 100–180 μm; with Scutellospora 2.0–4.0 μm long protuberances formed by the structural, projecturata laminated layer of the outer wall 7a Spores with two-type ornamentation on spore surface; spores Scutellospora pale orange brown to dark orange brown, 130–180 μm in diam; dipapillosa with small conical warts and additional blunt, bacilliform larger projections on the spore surface 7b Spores with warted projections having central secondary Scutellospora projections in the tip; spores cream to yellow, 100–170 μm in crenulata diam (continued) Appendices: Keys to Taxa Glomeromycota Species 151

(continued) 8a Spores subhyaline to pale straw to pale greenish-yellow, (100–) Scutellospora 150–300 (–500) μm in diam, generally ellipsoid to oblong, with calospora bi-layered middle wall 8b Spore yellow to greenish-yellow; 140–240 μm in diam, Scutellospora generally globose to subglobose, with one layered middle wall dipurpurescens 9a Spores golden yellow to dull yellow, (130–) 200–420 (–520) μm Scutellospora aurigloba 9b Spores dark yellow to brown yellow (to yellow brown), Scutellospora 105–150 μm, outer spore wall strongly expanding in lactic acid pernambucana based mountants Racocetra 1a Spores without ornamentation on outer wall 2 1b Spores with ornamentation on outer wall 3 2a Spores light colored 4 2b Spores creamy-brown to brown-sienna, 170–370 μm in diam Racocetra castanea 3a Surface ornamentation with spines or warts generally <2.5 μm in 5 diam 3b Surface ornamentation with projections generally >2.5 μm in 6 diam 4a Spores hyaline to pale straw to pale yellowish-cream, 160– Racocetra fulgida 250 μm in diam 4b Spores pale to dark pink, 120–170 × 130–420 μm in diam; outer Racocetra wall staining yellow to yellow orange in Melzer’s reagent alborosea 5a Spore surface with fi ne spines; spores pinkish-orange to Racocetra persica brownish orange, 270–390 μm in diam 5b Spore surface with crowded rounded warts, spores pale straw to Racocetra yellow to light orange brown, 220–480 μm in diam verrucosa 6a Spores red brown to dark brown with rounded projection on 7 surface 6b Spores dark brown, 300–460 μm in diam, with coralloidic warts Racocetra coralloidea 7a Spores red brown to dark brown, 250–450 μm in diam; with Racocetra rounded dome-shaped warts gregaria 7b Spores brown to dark brown; 90–180 μm in diam; warts on top Racocetra minuta with central depressions Cetraspora 1a Spores without ornamentation on outer wall 2 1b Spores with ornamentation on outer wall 3 2a Spores hyaline to white 4 2b Spores apricot yellow to yellow brown, 140–240 μm in diam Scutellospora armeniaca 3a Spores with a fi ne dense spiny ornamentation on outer spore Cetraspora wall; spores ochraeous to fulvous or rust, 130–230 μm in diam spinosissima 3b Spores ornamented with fi nger-pink-like processes in planar Cetraspora view; spores ochraeous yellow with a pinkish tint, 110–190 in striata diam (continued) 152 Appendices: Keys to Taxa Glomeromycota Species

(continued) 4a Spores brilliant hyaline, white to rarely pale grey, generally Cetraspora globose to subglobose; germination shield generally not seen pellucida 4b Spores hyaline, becoming creamy under storage in formalin; Cetraspora globose to subglobose to ellipsoid; 200–320 μm in diam; gilmorei sporogenous cell brown; germination shield generally easy to observe Dentiscutata 1a Spores without ornamentation on outer wall 2 1b Spores with ornamentation on outer wall 3 2a Spores hyaline, white to light olive, 350–750 μm in diam Dentiscutata scutata 2b Spores pale orange brown to red brown, 200–300 μm in diam; Dentiscutata outer wall not staining in Melzer’s reagent; second middle wall hawaiiensis layer fracturing with a series of rectangular and V-shaped notches 3a Spores with a single ornamentation on outer spore wall 4 3b Spores with double ornamentation on outer spore wall 5 4a Spores hyaline to white, globose to ovoid, 170–370 μm in diam; Dentiscutata with spiny papillae ornamentation cerradensis 4b Spore with papillae surface ornamentation on outer wall; Spores Dentiscutata light brown, globose to ellipsoid, 150–260 μm in diam heterograma 5a Spores with double ornamentation on the outer spore surface 6 5b Spores with each one papillae ornamentation both on outer and Dentiscutata inner surface of the outer wall; yellow-brown to brown, biornata 120–260 × 450–500 μm in diam 6a Spores orange brown to dark red brown, 200–470 μm in diam; Dentiscutata having spines in the depressions of a reticulum reticulata 6b Spores dark brown to black, 290–500 (–1050); with rounded pits Dentiscutata and a sinuous secondary ornamentation below nigra Fuscutata 1a Spore without surface ornamentation on outer wall 2 1b Spore with surface ornamentation on outer wall 3 2a Spores hyaline to white; oblong-ellipsoid to long ellipsoid, Fuscutata 280–580 × 210–370 μm in diam savannicola 2b Spores dark orange brown to dark red brown, 140–220 μm in Fuscutata rubra diam, outer and innermost wall strongly staining in Melzer’s reagent 3a Spores hyaline to subhyaline, globose to oval, μm in diam; Fuscutata spores with fi ne spiny ornamentation on the surface of the outer trirubiginopa wall 3b Spore with papillae ornamentation on the surface of the outer Fuscutata wall; spores red brown to dark brown, globose to oval, heterograma 159–295 μm in diam Quatunica 1a Spores white-yellow, to yellow-brown, 340–640 μm in diam Quatunica scutata 1b Spores orange-brown to dark red brown, 200–650 μm in diam Quatunica erythropus About the Author

This handbook was written while Tancredo Souza was an exchange student at the Department of Life Sciences, University of Coimbra, Portugal. His research focus on the effects of biological invasions on the arbuscular mycorrhizal diversity from the Brazilian xeric shrubland. His interests are in the Plant-AMF interactions, ecology of mycorrhizal fungi, microbiology and process. He holds degree in Agronomy (B.Sc.), Soil and water management and conservation (M.S.) and Soil sciences (Ph.D.) from the Federal University of Paraíba, Brazil and University of Coimbra, Portugal.

© Springer International Publishing Switzerland 2015 153 T. Souza, Handbook of Arbuscular Mycorrhizal Fungi, DOI 10.1007/978-3-319-24850-9