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
Mistletoe relatives
• Commandra
umbellata, bastard
toadflax
• Euonymus americanus,
brook euonymus
Control?
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.
Costa Rica
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 ballmoss
Tillandsia recurvata, small ballmoss
Close relatives
• Tillandsia baileyi
Gulf Prairies and Marshes
South Texas Plains
Control?
• Tillandsia recurvata
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 3000
sodium bicarbonate (baking soda)
potassium bicarbonate (Kaligreen,
Arysta; MilStop, BioWorks)
Spanish Moss
• Class Liliopsida
• Family Bromeliaceae
• Tillandsia usneoides, spanish moss, blackmoss,
pastle
Light fragrance at night
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.
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.
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/span
moss.htm
Interactions among epiphytes
• Nonvascular epiphytic species (lichens) affect the
quality of host tree for T. usneoides (spanish
moss)
• 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
Crustose
Squamulose
Foliose and Fruticose
Leprose