ROOT DISEASES LAMINATED ROOT ROT Phellinus sulphurascens Pilát [Phellinus weirii (Murr.) Gilb.] Hosts-- Douglas-fir and grand fir are most susceptible. Western hemlock and subalpine fir are less susceptible and other conifers in northern Idaho and Montana are tolerant or resistant. Also see: Cedar laminated butt rot, p. 26. Distribution-- The range of Douglas-fir or true firs in northern Idaho and northwestern Montana. Damage-- Mortality or windthrow. Decays roots and kills cambium of roots and root collar. Trees of all ages are killed by girdling the cambium and decaying the sapwood. Mortality occurs in large disease centers and in small groups. Infected trees often are attacked by bark beetles as well. Identification-- Infected trees have typical root disease crown symptoms. Freshly cut stumps often have brown or red-brown stain in the sapwood and outer heartwood indicative of the early stages of decay (fig. 124). Conks are rare and indistinct (fig. 125). Most diagnostic is the thin layer of cream- to dark yellow-colored mycelium covering the outer bark of infected roots (fig. 126). Fuzzy, cinnamon-colored mycelium often occurs in bark crevices along with the cream-colored mycelium. Infected trees occasionally have some basal resinosus. Decayed wood separates easily along the annual rings and is extensively pitted with small white- or cinnamon-colored pockets (fig. 127, 128). Trees with rotten roots are prone to windthrow. Some trees develop butt rot from this disease long before they are killed. Similar damages-- Armillaria root disease also causes basal resinosus but white mycelium fans of Armillaria are present under the bark in the cambial region rather than on the exterior of roots. References-- See full guide. Figure 124. Brown stain is sometimes seen in the sapwood or outer heartwood of trees with laminated root rot. Figure 125. Conks are rare. They grow on a root or fallen stem of a tree killed by laminated root rot. They are thin, leathery when fresh and friable with age, light weight, yellow to cinnamon brown with small pores. 82 ROOT DISEASES Figure 126. Cream- or yellow to cinnamon-colored mycelium is found on the outer bark of roots with laminated root rot. Figure 127. Decay from laminated root rot separates easily at the annual rings and is pitted with tiny holes. Cinnamon-brown mycelium and and tiny hair- like hyphae (setal hyphae) are often found in the decay. Figure 128. Decay from laminated root rot has distinctive, pinhead-sized round pits. 83 ROOT DISEASES TABLE 3. COmpaRING IMPORTANT ROOT DISEASES. OTHER BASAL FUNGUS HOSTS DECAY DISTINGUISHING RESINOSUS CHARACTERISTICS DF, GF, WF, RF, SAF, ES White or Thick fan-shaped Armillaria sapling yellowish, felts of white Yes ostoyae pines stringy with mycelium under black zone lines bark All conifers Cream-colored Laminated, mycelium on outer DF, GF separating at bark of roots Phellinus annual rings, under duff; Yes sulphurascens Other pitted with cinnamon-yellow conifers pinhead-sized mycelium in bark holes cracks with cream mycelium Conks shelving or DF, GF, appressed in SAF, WF, hollow stumps or Heterobasidion RF occidentale White or on roots Other yellowish, underground; conifers stringy to upper surface No somewhat brown, lower laminate; pored cream color irregular white with brown non- Heterobasidion PP pockts with pored margin; black flecks cream-colored irregulare Other pines rarely mounds (button conks) on seedling roots Small roots with red-brown resinous center; galled roots; large DF Brown cubical brown, velvety Phaeolus No rot of root and conks with green schweinitzii Other butt heartwood or brown pore conifers layer on underside; produced on ground or tree base Black or dark Leptographium PNP, PP No decay brown stain in No wageneri produced sapwood follows LP, DF annual rings Red-brown or brown stain in root; conks 2-5 ES, BS, LPP White pocket Onnia inches, yellow to rot with large, tomentosa No cinnamon upper Other spindle-shaped surface; with short conifers empty pockets stipe; cream to tan poroid lower surface BS=Colorado blue spruce, DF=Douglas-fir, ES=Engelmann spruce, GF=grand fir, LPP=lodgepole pine, PP=ponderosa pine, PNP=pinyon pines, RF=red fir, SAF=subalpine fir, WF=white fir. 77 STEM DECAY TABLE 1. COmpaRISON OF COMMON HEARTWOOD ROTS. FUNGUS HOSTS CONKS Shape Upper Lowe r and surface surface Context Location Echinodontium GF, WH, Tan; teeth tinctorium Hoof, under Brown, Orange SAF branch woody projecting Indian paint downward DF, LPP, Phe llinus pini WL Hoof or flat Dark Cinnamon to Cinnamo n Pini or Other on bark brown tan red ring rot conifers Onnia ES, LPP Mushroom- Gold to tomentosa like with brown, Tan to gold, Gold, leathery cap velvety; brown with brown with Other and central age; pores. age Tomentosus conifers 1-4 inch root disease stalk. On diameter ground Phaeolus DF Non-woody; Green when schweinitzii Brown, fresh, brown Brown thick shelf or velvety Other on ground with age; Root & butt rot conifers large pores Fomitopsis WL, PP Hoof or Ye llow, Yellow- officinalis cylindric, Ye llow or white; white, or white; pored Other large cream chalky Brown heartrot conifers consistency Fomitopsis Ve ry Brown, Cream; pinicola All dead common; gray, red Cream; conifers corky thick shelf or band at small pores consistency Red belt fungus hoof margin Heterobasidion GF, ES, Thin hoof or Cream; spp. WH, WPP, flat on bark, small pores; Leathery Gray or when fresh, SAF, DF inside hollow brown margin Annosus root stumps or on brown with woody disease PP roots age with age Phellinus Conks very GF, DF, Tan; brown sulphurascens rare; thin, flat with age; WH on bark; light none Brown or SAF fuzzy setal yellow-tan Laminated weight, brittle hyphae root rot with age Phellinus Conks are uncommon. Phellinus weirii (p. 26) and we irii P. sulphurascens (p. 82-83) are differentiated WR C mostly on the basis of host, although there are Cedar laminated butt microscopic differences in conks and cultural rot characteristics. Postia Conks rare; White or sericeomollis ve ry thin, flat White or cream; WR C on bark or none cream, small very thin; Cedar brown decayed pores brittle with pocket rot wood; bitter age Host key for Table 1 (p. 34): DF=Douglas-fir, ES=Engelmann spruce, GF=grand fir, 34 LPP=lodgepole pine, PP=ponderosa pine, SAF=subalpine fir, WH=western hemlock, WL=western larch, WWP=western white pine, WRC=western redcedar STEM DECAY TABLE 2. DECAYS OF COMMON HEARTWOOD ROTS. FUNGUS DECAY NOTES Echinodontium Ye llow to orange, stringy; Conks common tinctorium confined to heartwood Red-brown discoloration in heartwood; pronounced white, Phellinus pini spindle-shaped pockets with Punk knots and conks firm brown wood between; common becoming stringy, white decay in most advanced stages Root disease; fruiting Pronounced white or hollow Onnia tomentosa bodies leathery, pockets, honeycomb mushroom-like, and rare appearance in cross section in this region Brown cubical decay of stem Root disease; conks and root heartwood; thin, common on ground, Phaeolus schweinitzii resinous felts may be present occasional on butt; dark in shrinkage cracks of decay red-brown heart in small roots Brown cubical decay of stem Conks rare; infections Fomitopsis officinalis heartwood only; thick, white, generally high in tree; mycelium felts in shrinkage not originating from cracks roots Brown cubical decay of both Dead trees and stumps; sapwood and heartwood; decay not restricted to Fomitopsis pinicola forms crumbly decay with heartwood; conks firm cubes common Root disease; butt Heterobasidion White rot; somewhat heartrot common in old laminating, stringy, with grand fir, hemlock, occidentale and irregular white pockets and H. irregulare spruce, cedar, and small black flecks ponderosa pine Decay is distinctly laminating Root disease; butt Phellinus weirii along the annual rings; tiny heartrot common in live and white pockets or hollow pits grand fir, hemlock, P. sulphurascens throughout; often filled with white pine, and cedar cinammon-brown setal hyphae (comments in Table 1) Brown cubical decay in large Heartrot very common Postia sericeomollis pockets (several inches to in western redcedar several feet in length) 35.