The Genus Vallisneria Linne

By Bob Fenner

Vallisneria americana, a Jungle Val. in aquarium and in Florida in a drainage ditch

Amongst the most hardy and undemanding aquatic plants, Vallisnerias are easily grown in most aquariums. Their easy requirements are nutrient bearing gravel, lots of light and careful initial planting (with their white crown bases barely above gravel.

Vals are great for backgrounds, tank sides and central areas where high relief is desired. The genus is probably the most widely offered in the hobby; and the lowest cost to purchase and cultivate. Don't worry about killing them off, you will probably have to periodically thin out these plants to reduce their dense thickets.

Distribution & Classification

The genus is widely distributed over a large part of the globe, fresh to brackish, tropics to semi-temperate, naturally and through human introduction.

Vallisneriaare members of the monocotyledon family Hydrocharitaceae. This group that should be familiar to aquatic horticulturists as it also contains other important genera; Elodea (anacharis), the beautiful heart-shaped Limnobium and notorious Hydrilla verticillata, among others.

The Vallisnerias are superficially similar to the equally popular and appropriate arrowheads, genus Sagittaria. These look-alikes have pointier leaves, whiter, thicker roots and different venation in their leaf structure. Sag's typically bear darker green, stiffer leaves than vals.

There are about ten species of Vallisnerias, but good luck sorting them out. There is much confusion in the trade and literature on the common and scientific naming of these species and their hybrids and sport mutations. But as William Shakespeare wrote, "what's in a name"? Don't let labels dissuade you from trying the vals; they're all good.

The Players:

Vallisneria spiralisLinnaeus is the beginning of the 'name game' trouble. This plant is named for the long spiraling stalk of its female flowers, but among its many synonyms and cultivar varieties are many surprisingly different structural types.

V. spiralishas one sub-form, termed "forma tortafolia", a sport mutation labeled V. tortissima and other 'contortionist' races that are variously sold as "spiral, corkscrew, twisted..." Val in the trade. The common names for the "parent" species include "tape grass" and "straight Val". Does this seem confused? You bet. There are many sports worldwide that have been named for variations in their leaves; Vallisneria spiralis forma portugalensis, V. s. forma nana, V. s. forma pusilla, V. s. forma gracilis. And the fun doesn't stop there; synonyms (invalid same species names) Vallisneria americana, V. jaquinii, V. linnei, V. minor are only the beginning of misnomers (see Roe). I'll never complain about African cichlids again.

V. spiralisplants can be distinguished from other vals and Sagittarias on the basis of the 'veins' in their leaves. They have five "ribs" which end parallel at the leaf tip. The middle vein is flanked by one thick and one thin vein near the leaf edge.

Anyway, all of the V. spiralis same species and varieties are very good aquarium plants. Some stay less than a foot high with leaves about a quarter inch, others get to about twice as tall and wide. Some have straight, others varyingly tightly corkscrew wound leafing. Here's an image of V. spiralis in an aquarium.

Vallisneria giganteaGraebner is like its name sounds the 'true' giant val. This is the largest species, growing to over six feet; for larger aquaria or even sub-tropical ponds. It originated in New Guinea and the Philippines, but we grow it outside all year round in my home-town of San Diego, California.

Leaves with seven veins, available sometimes in a beautiful red which changes back to green with increased lighting. This species is best blind potted to facilitate moving, re-fertilization.

Vallisneria asiaticaMiki, 1934. Naturally distributed in temperate areas of Asia. Ribbon-like non-twisted leaves, 16-24 " long, up to 1/3 " wide. Imported since 1970, often sold as V. spiralis; don't you hate common names?

Vallisneria neotropicalisMarie Victoria, 1943. Distribution Southern U.S., Cuba. Color deep green to reddish. Often offered as American, giant, Italian Val in the west. To five foot long; large tanks only. One large central mid-rib with 4 long veins in every leaf.

Cultivation Notes:

Vallisneriaenjoy moderate pH's (6-7.5). Most species do well in tropical temperatures, 72-86 degrees Fahrenheit. V. gigantea will grow into the fifties. As regards mineral content, the water should not be too hard, a KH of 15 degrees or lower is best. Should your water start too hard from its source, you might consider mixing it with non-hard water (R.O., deionized), use of an acidifying agent, or transfer 'old' water from another system.

Substrate size and depth, with or without undergravel filter use is relatively unimportant. Silica sand or washed gravel will do with no supplementation other than fish wastes generally necessary or desirable. The larger species I would blind pot to facilitate moving and re-fertilizing, others do fine without utilizing peat, soil or other media placed under the gravel. Care in planting is far more important. Take care to not bury more than the root base of these plants, nor to get gravel between and amongst their leaf base. To plant gently drag the plants' roots under the gravel pulling the crown above the gravel at it's white base.

Lighting cannot be practically too great in terms of strength or duration. The best light source for these and other specialty live-plant tanks is still full-spectrum fluorescents (e.g. Vita-lite), but most types of illumination will sustain these plants. If your plants don't seem to be growing, increase duration. Where in doubt, extend the daylight.

Propagation:

Occurs via two mechanisms, sexual by flowering and asexually through vegetative 'runners'.

Vallisnerias are dioecious, with separate male and female flowering plants. These flowers appear on special stems that can grow as much as 2 cm. (1/2 inch) per hour. The male flower spathe is short and releases male flowers near the base of the plant that rise to the surface pollinating the long-stalked female flowers. On fertilizing these coil and ripen underwater.

Display, Competition:

The genus Vallisneria grows and shows well with those other hardy favorites the Cryptocorynes (crypts), Ceratopteris (water fern), Hygrophilas, Aponogetons, elodeas, and the South American Swordplants in the genus Echinodorus.

Some other writers and friends have stated that for whatever reasons that the genera Sagittaria and Vallisneria do not mix well in the same system. Perhaps sags prefer higher calcium concentrations than vals; maybe one produces allelopathogenic chemicals that mal-affect the other? To my experience there are no difficulties in mixing the two; I've done it and seen many instances of other folks growing them together, luxuriantly.

Collecting Your Own:

Can be done as various varieties are to be found around the world. The usual words of caution here: 1) Check for permits in your area. 2) Do not, for any reason, place/replace plant stocks where they can 'get loose' in the wild 3) Do carefully inspect wild-collected plants, dip in alum, potassium permanganate, other prepared solution to remove unwanted pests, pollution and parasites and 4) definitely quarantine for a good two weeks plus...

Conclusion:

Despite the perplexing naming, cross common-naming of the various vals, these are rightly the most popular aquarium plants. They are tolerant of an amazing range of water qualities, lighting conditions and quantities and do just fine with any type of substrate and simple fish 'manure' fertilization.

Simply plant them crown-out of the gravel in an area where you want something tall, and watch them grow.

Bibliography/Further:

Baensch, Hans A. Aquarium Atlas, Vol. 2. Tetra Press, 1212 pgs.

Brown, Phillip J. 1977. Vallisneria. TFH 4/77.

Brunner, Gerhard. 1973. Aquarium Plants. T.F.H. Publ., N.J.

Gasser, Robert A. 1979. Contortionist Val. FAMA 2/79.

James, Barry. 1986. A Fishkeepers Guide to Aquarium Plants. Tetra Press, Salamander Books, U.K.

Prescott, G.W. 1969 How to Know the Aquatic Plants. Wm C. Brown Co., Iowa.

Roe, Colin D. 1967. A Manual of Aquarium Plants. Shirley Aquatics, Ltd.

Stodola, Jiri. 1967. Encyclopedia of Water Plants. T.F.H. Publ., N.J.

Graphics:

1,2) Two transparencies of the highly variable V. spiralis, labeled and sold as "jungle Val" in the western U.S.. The first clearly shows asexual reproduction via 'runners', as well as the namesake 'spiral' female flower stalk. The outdoors picture is from southern Florida where this plant is a contaminant (unwanted foreign species) growing in a drainage canal.

3) For comparison the more stout, bluish green-bean colored Sagittaria (S. sagittifolia).

4,5) Two poor aquarium shots of V. spiralis tortifolia showing the off its beautiful twisted appearance.

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