Hydrilla, also known as water thyme, is among several types of invasive aquatic plants that the Natural Resources Commission has recently banned the sale of in Indiana.
Effective Aug. 31, it will be illegal to sell 28 invasive aquatic plants in Indiana.
The new rule, which was recently approved by the Indiana Natural Resources Commission, also makes offering such plants for gift, barter, exchange or distribution illegal.
The purpose of this rule is to help prevent the introduction and distribution of aquatic invasive plants into Indiana waters and wetlands.
The spread of invasive aquatic plants reduces boating, fishing and other aquatic recreation opportunities. Such plants also negatively impact native aquatic plants and reduce property values around lakes and ponds.
The following are prohibited invasive aquatic plants and are declared pests or pathogens regulated under this section:
(1) Azolla pinnata (mosquito fern)
(2) Butomus umbellatus (flowering rush)
(3) Caulerpa taxifolia (caulerpa or Mediterranean killer algae)
(4) Egeria densa (Brazilian elodea, Brazilian waterweed, Anacharis, or Egeria)
(5) Eichhornia azurea (anchored water hyacinth)
(6) Hydrilla verticillata (Hydrilla or water thyme)
(7) Hydrocharis morsus-ranae (European frogbit or common frogbit)
(8) Hygrophilia polysperma (miramar weed, Indiana swampweed, or hygro)
(9) Ipomoea aquatica (Chinese waterspinach or swamp morning-glory)
(10) Iris pseudacorus (yellow flag iris or tall yellow iris)
(11) Lagarosiphon major (oxygen weed or African elodea)
(12) Limnophila sessiliflora (Asian marshweed or ambulia)
(13) Monochoria hastata (monochoria, arrowleaf, or false pickerelweed)
(14) Monochoria vaginalis (heartshape or false pickerelweed)
(15) Myriophyllum aquaticum (parrot feather or parrot feather watermilfoil)
(16) Myriophyllum spicatum (Eurasian watermilfoil)
(17) Najas minor (brittle naiad or brittle water nymph)
(18) Nymphoides peltata (yellow floating heart)
(19) Ottelia alismoides (duck lettuce)
(20) Potamogeton crispus (curlyleaf pondweed)
(21) Sagittaria sagittifolia (arrowhead)
(22) Salvinia auriculata (giant salvinia)
(23) Salvinia biloba (giant salvinia)
(24) Salvinia herzogii (giant salvinia)
(25) Salvinia molesta (giant salvinia)
(26) Sparganium erectum (exotic bur-reed)
(27) Trapa natans (water chestnut)
(28) Typha angustifolia (narrow-leaf cattail)
Many of these invasive plants have been used in aquariums or water gardens for years. Some are already widely established. The most popular of such plants currently sold include flowering rush, Brazilian elodea (Anacharis), yellow flag iris, parrot feather and yellow floating heart.
Management or eradication of species already in Indiana waters easily exceeds $1 million annually when Department of Natural Resources and lake association costs are combined.
Aquarium and water garden hobbyists can help slow the spread of such species by purchasing non-invasive or native plants. Boaters can remove plants, mud and other debris from their watercraft when they remove them from the water.
The new rule will be administered by the DNR Division of Entomology & Plant Pathology in cooperation with the Division of Fish & Wildlife. For information call Eric Fischer, DNR aquatic invasive species coordinator, (317) 234-3883.