Mistletoe, Ball moss, Spanish moss, and Lichens in Trees
Mark C. Black, Extension Plant Pathologist, Texas AgriLife Extension Service, Uvalde
Biological interactions• Neutralism - fitness of one species has no effect
on fitness of other (unlikely!)• Commensalism – epiphyte benefited, tree neither
benefited or harmed• Mutualism (symbiosis)- species derive a mutual
benefit• Parasitism - one organism takes from the host for
a long time• Hemiparasitism - takes water and nutrients from
the host, but is photosynthetic and makes some products
• Competition – one species limits space, sunlight
Mistletoe
• Class Magnoliopsida
• Family Viscaceae, 2 genera in Texas
• Diversity Trans Pecos > Edwards Plateau > rest of Texas
• Arceuthobium (dwarf-mistletoe) Phoradendron (mistletoe)
• Phoradendron tomentosum, injerto, Christmas mistletoe
Plant Epiphytes• Autotrophic• Derive only physical support, not
nutrition from the host• May damage the host• Attach to their host high in the
canopy• Large epiphytes occur most
abundantly in moist tropical forests, but mosses and lichens occur widespread as epiphytes with trees.
Ball Moss
• Class Liliopsida• Family Bromeliaceae, 2 genera in Texas• Diversity S, E Texas > N Texas• Hechtia (false agave)
Tillandsia (ballmoss,spanish moss)
• Tillandsia baileyi, Bailey ballmossTillandsia recurvata, small ballmoss
Ball moss
Water from condensation on extensive foliar trichomes.Trace minerals from dust.
Part of their nitrogen from decomposition of insects.
Pseudomonas stutzeri, nitrogen-fixing bacterium isolated from interior of T. recurvata.
Ball moss control
• Hand removal
• Chemicals – Kocide 3000sodium bicarbonate (baking soda)potassium bicarbonate (Kaligreen, Arysta; MilStop, BioWorks)
Spanish Moss• Class Liliopsida
• Family Bromeliaceae
• Tillandsia usneoides, spanish moss, blackmoss, pastle
Leaves covered with cup-like, permeable scales that 'catch' moisture and nutrients from the air. In extreme dry spells, the plant becomes dormant until moisture returns.
The plant is not parasitic, but it can sometimes damage the host tree by over-shading the leaves, thus reducing photosynthesis, or by weighing down and breaking the branches.
Up to 20 feet long.
http://www.sfrc.ufl.edu/4h/Spanish_moss/spanmoss.htm
Host preference?
Spanish moss commonly adopts oak or cypress trees as hosts, but less common on pine, etc.
Chiggers (redbugs) are common residents in Spanish-moss on the ground.
Interactions among epiphytes• Nonvascular epiphytic species (lichens) affect the
quality of host tree for T. usneoides (spanishmoss)
• T. usneoides grew faster on live oak with a dominant lichen than when lichen was hand picked
• Extract of lichen common on poor hosts reduced T. usneoides seedling survival and growth compared to other lichens and rainwater
• Lichens increased T. usneoides seeds and strands that adhered to Ilex opaca (poor host) but not Q. virginiana
Lichens• "Lichens are fungi that have discovered agriculture"--
lichenologist Trevor Goward• Spores• Non-sexual reproductive packages• Breakage when dry to blow, wash away, be carried• Able to shut down metabolically during unfavorable
conditions• Very slow growth, often < 1 mm/yr; some may be
among oldest living things on earth• Environment (fix N), wildlife (tundra), people (dye, etc.)• Indicate good air quality
Lichens• Composite organisms consisting of a
symbiotic association of a fungus with a photosynthetic partner, usually a green alga and/or cyanobacterium. The morphology, physiology and biochemistry of lichens are very different to that of the isolated fungus and alga in culture.
• The algal partners are far less numerous than fungal partners.
• Each lichen species contains a different species of fungi (20% of all) and so it is according to the species of fungi that lichens are classified.
• 13,500 to 17,000 species