Name: Ganoderma meredithiae
Author: Adask. & Gilb.
Citation: [as ‘meredithae’] Mycotaxon 31(1): 251 (1988)
Restricted to pines. http://www.cybertruffle.org.uk/...
GANODERMA MEREDITHAE Adaskaveg and Gilbertson, sp. nov.
Holotypus: JEA 345, on Pinus taeda L., R. Summers, Pineville, Grant Parish, LA, Aug. 21, 1985; in herb. National Fungus Collections, Beltsville, MD.
Etymology: named for Dr. Meredith Blackwell of Louisiana State University, a student of Gulf Coast fungi.
Basidiocarps annual, sessile to centrally or laterally stipitate, developing at the base of living pines or on dead pines or stumps; pilei circular to dimidiate or reniform, up to 15 cm or more broad, upper surface cream colored to yellowish buff at first, becoming reddish brown, concentrically zonate and shallowly sulcate, glabrous, dull and crustose to shiny and laccate; pore surface creamy white at first, becoming pale vinaceous cream at maturity, pores circular to angular, 4-6 per mm, with thick, entire dissepiments that have a sugary appearance under a 30X lens; stipe central to lateral, up to 10 cm long and 3 cm thick, becoming dark maroon, shiny, and laccate, cut surfaces showing distinct dark zones of dense purplish brown tissue under an outer zone of uniformly pale buff tissue, in cross sections these dark zones appear as concentric rings; context light buff near the upper surface, grading to pale purplish brown toward the tubes, corky, usually with some darker resinous zones, up to 2 cm thick; tube layer light purplish brown, corky, up to 2 cm thick.
Hyphal system dimitic; contextual skeletal hyphae thick-walled, hyaline, nonseptate, faintly pigmented in mass, 2-6 :m in diam with frequent branching, tips often dendritically branched; contextual generative hyphae difficult to discern in mature specimens, thinwalled, hyaline, with clamps, 2.5-4.5 :m in diam; tramal hyphae similar, generative hyphae more obvious; pilocystidia forming a solid palisade on the pilear surface, moderately thick-walled, often much thickerwalled at the apex, strongly amyloid in Melzer’s reagent, highly variable in shape from nearly spherical or reniform to clavate, often strongly branched or lobed, 17-50 × 6-15 :m. Cystidia or other sterile hymenial elements absent. Basidia broadly clavate to subspherical, with a sharply narrowed base, 4-sterigmate, 22-26 × 13-16 µm.
Basidiospores ellipsoid, apex truncate with a germ pore, pale brown in KOH, wall two-layered with layers separated by inter-wall pillars, 9.5-11.5 × 5.5-7.0 :m.
Type of rot – White root and butt rot of living pines.
Substrata – Restricted to Pinus, causing a white root and butt rot of living trees and also continuing decay and fruiting on dead trees and stumps. Known from Pinus taeda L. (loblolly pine) and Pinus glabra Walt. (spruce pine).
Distribution – Apparently through the Gulf Coast region from east Texas to Georgia.
Ganoderma collections from pine in the past have been referred to as Ganoderma lucidum, G. curtisii (Berk.) Murr. or G. tsugae. Our concept of G. Iucidum is that it occurs only on hardwoods. It is consistently characterized in North America by production of distinctive chlamydospores in culture and an optimum temperature range of 30-35 C with some growth up to 42 C. Ganoderma tsugae occurs mainly on conifers and occasionally on birch in northern latitudes. It has an optimum growth temperature of 20-25 C and does not grow above 30 c’. Ganoderma tsugae is a common species in the northeastern and northcentral United States and eastern Canada on Tsuga and in southwestern United States on Abies. These main hosts are associated with species of pine. However, Ganoderma tsugae has rarely been reported on pine in these regions. Ganoderma meredithiae has an optimum growth temperature of 25-30 C, with growth up to 35 C, and produces plumose or feathery mats. Furthermore, G. tsugae and G. meredithae differ in morphology of pilocystidia and basidiospores (Adaskaveg and Gilbertson, 1988). It is not reasonable to consider the southern pine Ganoderma to be G. tsugae. Ganoderma curtisii has been recognized as distinct from G. lucidum by Overholts (1953) and others on the basis of having stipitate basidiocarps. However, it is established that G. Iucidum and G. meredithae basidiocarps vary from stipitate to sessile and, at least with G. lucidum, cultures from sessile basidiocarps will produce stipitate ones (Adaskaveg and Gilbertson, 1986c). The neotype of G. curtisii at Kew has a part of the substratum adhering to it and we have identified this as hardwood bark, probably of oak. It is certainly not pine bark. Resinous zones considered by Steyaert (1930) to be an important character of G. curtisii are typical. of G. meredithae but also occur in G. lucidum. The macro- and microscopic morphological characters of the neotype of G. curtisii fit our concept of G. lucidum and there is no reason to consider G. curtisii as anything other than a synonym of G. lucidum (Adaskaveg and Gilbertson, 1986c). Steyaert (1980) described G. ravenelii as a new species based on a portion of the former neotype of G. curtisii, considering that portion to have different spore and context morphology than the rest of the G. curtisii neotype. Our examination of the specimen designated as the holotype of G. ravenelii by Steyaert indicates that it does have spores that are more narrow than those of the G. cur tisii neotype. Basidiospores of the G. ravenelii holotype are different from those of G. meredithae and are more like those of G. zonatum, a species found on palms from the southeastern United States (Adaskaveg and Gilbertson, 1986b). However, there is no information on the substratum of the G. ravene1ii holotype. There is no reason to believe it was on pine and no reason to apply the name G. ravenelii to the pine Ganoderma. When all of the evidence from basidiocarp morphology, cultural characteristics, temperature relationships, substratum relationships, and geographical distribution are considered the only defensible and logical alternative is to consider the pine Ganoderma to be a species distinct from the other members of the G. Iucidum complex in North America (Adaskaveg and Gilbertson, 1986a,b,c, 1988). Some species of Ganoderma on conifers (i.e., G. carnosum Pat., G. atkinsonii Jahn, Kotl. and Pouzar) from Europe and other regions unfortunately have not been characterized as to cultural morphology and it is not possible to draw any conclusions on the application of any of these names to North American Ganoderma species. Stalpers (1978) considers G. valesiacum Bourd. of Europe a synonym of G. tsugae.
The distinguishing characteristics of G. meredithae are the restriction to pines, the frequently lobed or branched pilocystidia, the plumose or feathery mats produced in culture, the lack of chlamydospores, and the optimum growth temperatures of 25-30- C, intermediate between G. lucidum and G. tsugae. Its temperature relationships are similar to those of G. zonatum (Adaskaveg and Gilbertson, 1986a). However, G. zonatum differs in several respects including host specificity (on palms), distinctive, narrow basidiospores, and different cultural morphology. http://www.mycobank.org/...
“Differences in colony growth rates were observed when Ganoderma species were grown on medium amended with water soluble sapwood extracts from each wood type. G. meredithiae had enhanced growth on all media amended with sapwood extracts, while G. curtisii, G. sessile and G. zonatum had slower growth on loblolly pine extract amended medium.”
Loyd, A. L., Held, B. W., Linder, E. R., Smith, J. A., & Blanchette, R. A. (2018). Elucidating wood decomposition by four species of Ganoderma from the United States. Fungal biology. https://www.sciencedirect.com/...
Ganoderma meredithiae is phylogentically the same as curtisii as far as dna sequencing goes.
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