Index
Introduction
Melinis minutiflora Beauv. (listed under the
Family Gramineae or Poaceae) also is referred to as Panicum
minutiflora and P. melinus. It is a seed propagated
tropical grass (C4) that grows to height of approximately 3 ft. It
originated in Africa, though it can now be found in much of South and
Central America, the Caribbean, and parts of India. M.
minutiflora is considered a nuisance weed in many parts of the
world including Hawaii, Brazil, Venezuela, and Colombia (Duke, 1983).
Hawaii is currently tracking its spread on the islands.
Most of the research with this grass has focused on its
nutritional value as a pasture grass. It can be an easy to establish
pasture grass. However, it also can outgrow all other grasses and
weeds in a pasture and form monotypic stands. Like many tropical
grasses, it does not make good hay or silage (although it is used for
hay and silage in some tropical countries). M. minutiflora
can be overgrazed and damaged from repeated mowings (e.g., for making
hay).
To learn more about the genus Melinis please refer to L.
Watson and M.J. Dallwitz's web site. James
A Duke's Handbook of Energy Crops (1983, unpublished) provides
nutrition information, as well as, chemical, medicinal, and ecology
information. The
University of Hawaii's web site has several pictures available of
M. minutiflora.
Common names for Melinis minutiflora include:
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Chemical Compounds and
Toxicity
Little is known about the chemical composition and
toxicity of M. minutiflora. Preliminary chemical analyses at
Cornell University indicate the presence of phenolics in the roots.
The volatile oil (from the glanular hairs) contains fatty acids,
esters, and probably phenolics (Duke, 1983). The leaves contain
calcium oxalate crystals (Lersten, 1983).
No toxicity studies could be found. Since little is known about
the chemical composition (beyond nutritionally important compounds),
it is difficult to assess the toxicity of the plant when used for
medicinal purposes. Some phenolics are poisonous, while others are
known to have antioxidant and anticancer properties.
Oxalates (including calcium oxalates) have caused adverse effects
in livestock and can decrease the availability of calcium in a plant.
For example, some of the calcium in alfalfa is in the oxalate form
and unavailable to ruminants. Ruminants tend to be more tolerant of
oxalates then non-ruminants (e.g., horses), because rumen microbes
degrade the oxalate. Therefore, if ruminants are slowly exposed to a
diet high in oxalates (over an approximately 4 day period), the
population of oxalate degrading microbes in the rumen increases
sufficiently to prevent oxalate poisoning. Given that M.
minutiflora is used as a pasture plant and that most treatments
with it are for external parasites, one might assume that the level
of oxalates will not cause adverse effects. However, oxalate levels
can vary with the growing season, so one should be cautious when
using any oral treatments with the grass, especially with
non-ruminants (Cheeke, 1998).
Studies need to be conducted to determine the types of phenolics and
other bioactive compounds in M. minutiflora, in order to
better assess its potential toxicity, identify the active compounds,
and determine variation in the compounds at different growth stages.
Uses and Efficacy
In the Dominican Republic, the roots of M.
minutiflora are used for internal parasite infections in animals.
The roots are washed, ground, mixed with water, and given as an oral
treatment. The anti-parasitic properties of M. minutiflora
are currently being studied at Cornell University. Preliminary tests
have been conducted with Haemonchus contortus. These tests
indicate that crude ethanol extracts of the grass decrease the
viability of H. contortus eggs. Further studies on the effect
on third stage larvae are underway.
M. minutiflora is insecticidal, arachnicidal, and an insect
repellent. In Tanganyika, the leaves are rubbed on livestock to
repell insects. Studies conducted by Mwangi, et al. (1995) and
Hernandez, et al. (1990), demonstrate that the grass repells ticks
(Rhipicephalus appendiculatus and Boophilus microplus).
Studies also have shown that M. minutiflora, when
inter-cropped with maize, repelled cereal stemborer females from
oviposting on the maize (Khan, et al. 1997).
References
Not all of the references in the list below were
used in writing this web page. They are included here so that a more
complete resource list is available for those interested in the
subject area.
This series of web pages was created by a graduate student at Cornell University. All comments and suggestions are welcome. If you would like to add to this medicinal plant database, please e-mail Webmaster.
WARNING: These web pages are only meant to be informative. Neither Cornell University nor the author of this site endorse or recommend the use of these plants.