Images of Licea Iridescens, a Corticolous Myxomycete Species New to Science, and Crystals of Unknown Origin on the Trunk Tree Bark of Living American Elm Trees

Submitted by: Harold W. Keller

Left: Close-up of myxomycete Licea iridescens sporangium showing black, apical, thickened patch of debris and smoother iridescent sides with bluish, reddish sparkles
This study concentrated on myxomycete biodiversity on the tree trunk bark sampled from living American elm trees located in nature parks in the Fort Worth, Texas, area. Moist chamber bark cultures yielded new species of Licea and crystals of unknown origin never before published in scientific literature. The light photomicrographs using multifocal imaging (10 to 70 images) and computer stacking shown here, highlight the iridescent bluish and reddish sparkles on the smooth wrinkled sides of the tiny sporangium about 100 micrometers in diameter. These imaging techniques, especially scanning electron micrographs, increase the depth of field and surface structural details seen, not possible with light microscope images taken in a single optical plane. Ed D. Forrester, a volunteer researcher at BRIT, took the light microscope photographs, and Billy G. Stone, a Laboratory Associate at BRIT, took the scanning electron micrographs. Vanessa M. Marshall, a volunteer student intern, and Harold W. Keller, a Resident Research Associate, were the authors. Hard copy saddle-stitched reprints are available by request: haroldkeller@hotmail.com. This is an ongoing study to identify and document more undescribed species of Liceas and the composition and origin of the crystals. If the Inoculum readership has additional information on tree bark crystals on bark of living trees, please contact Harold W. Keller.

Right: Scanning electron micrograph showing top half of sporangium with convex, debris, wrinkled smooth sides site of iridescence, and coffee-bean collapsed spores
Reference: Keller, H.W. & V.M. Marshall. 2019. A NEW IRIDESCENT CORTICOLOUS MYXOMYCETE SPECIES (LICEA: LICEACEAE: LICEALES) AND CRYSTALS ON AMERICAN ELM TREE BARK IN TEXAS, U.S.A. J. Bot. Res. Inst. Texas 13(2): 367–386.

Left: Field of larger and smaller irregular crystals associated with two sporangia of Licea iridescens. Note the convex thick black area of debris centered apically and the iridescent sides of bluish and red sparkles as seen with light microscope stacked images
Acknowledgment/Photo credit: Courtesy of J. Bot. Res. Inst. Texas 13(2), 2019, Botanical Research Institute of Texas.