Cryptocoryne thwaitesii Schott

^{Click on the picture to get the full image (ca 50 k)}

Cryptocoryne thwaitesii is quite variable in the color of the limb of the spathe. The presence of the red dots varies from almost absent to densely covered. coll. unknown photo Jacobsen	After some days the tail of the limb of the spathe bent forward. coll. NJ 75-14 photo Jacobsen	Note the fine undulated margin of the leaves of C. thwaitesii. The texture of the leaves is different from other Cryptocoryne, covered with small bulges. It feels like sandpaper. coll. unknown photo Bastmeijer	This plant was cultivated by Hans Ehrl (D). The leaves are almost black and reach up to 10 cm. coll. unknown photo Bastmeijer
Variations in the limb of the spathe... coll. Babics SRL01 photo Bastmeijer	Almost deep red, coll. Babics SRL01 photo Bastmeijer	Wide open, dense covered, coll. Tomey photo Bastmeijer	A more narrow form coll. unknown photo Bastmeijer
A wide open 'tail' is seldom seen, coll. Waser 90-1 photo Kettner	Creme with dark purple red dots in the throat. coll. Waser 02-2 photo Bastmeijer	A yellow limb of the spathe without any purple dots. coll. unknown photo Möhlmann	A white limb with a few red dots in the lower part of the throat. coll. unknown photo Kaburagi
The same variation in the coloring of the kettle. coll. Babics SRL01 photo Bastmeijer	Less dense spotted. coll. Waser 02-2 photo Bastmeijer	Even lesser spots. coll. Tomey photo Bastmeijer	Only a few red dots in the upper part of the kettle. coll. unknown photo Kaburagi
Also the tube may be red dotted on the inner side. coll. unknown photo Bastmeijer	Drawing of C. thwaitesii in De Wit (1990) drawing Ike Zewald	Drawing of C. thwaitesii in De Wit (1958) drawing Ike Zewald	C. thwaitesii grows, like C. alba and C. bogneri in the rainforest, South West on Sri Lanka

Cryptocoryne thwaitesii is not so easy to cultivate. At me it grows emersed in water with a low conductivity (< 200 muS/cm) and slight acid conditions, making a soil mixture with some beech tree soil appropriate for emersed culture. This plant is hardly to keep in an aquarium.
In the SW rainforest of Sri Lanka also grow C. alba and C. bogneri. Both the leaves and the spathe makes that the three species are not to be exchanged (until now at least).

Jan D.Bastmeijer, update June 2004

Literature:

Arends, J.C., Bastmeijer, J.D. & Jacobsen, N., 1982, Chromosome numbers and taxonomy in Cryptocoryne (Araceae).II., Nord.J.Bot. 2 : 453-463.
Bastmeijer, J.D., C. Christensen & N. Jacobsen, 1984, Cryptocoryne alba und ihre Variationsbreite, Aqua-Planta 1-84 : 18-22.
Bastmeijer, J.D. & C. Kettner, 1993, Die Cryptocorynen von Yahalawatta (Sri Lanka), Aqua-Planta 1-93 : 30-31.
Graaf, A. de & Arends, J.C., 1986, The occurrence of Cryptocoryne and Lagenandra (Araceae) on Sri Lanka, Nord.J.Bot. 6 : 757-764.
Hermsen, E.P., 1977, Cryptocorynen, Het Aquarium 47(11) : 282-287.
Jacobsen, N., 1976, Notes on Cryptocoryne of Sri Lanka (Ceylon), Bot.Notiser 129 : 179-190.
Jacobsen, N., 1977, Chromosome numbers and taxonomy in Cryptocoryne (Araceae), Bot.Notiser 130 : 71-87.
Jacobsen, N., 1982, Cryptocorynen, Alfred Kernen Verlag, Stuttgart.
Jacobsen, N., 1987, Cryptocoryne, in: A Revised Handbook to the Flora of Ceylon, Vol. VI: 85-99.
Kasselmann, C., 1995, Aquarienpflanzen, Ulmer, Stuttgart.
Möhlmann, F., 1987, Der Weisse Wasserkelch, Aquarien Magazin 21(11) : 436-438.
Möhlmann, F., 1993, Die Cryptocoryne-Arten Ceylons (1), Aqua-Planta 4-93 : 123-128.
Wit, H.C.D. de, 1958, A diminutive Cryptocoryne, C. thwaitesii is a little known species well worth cultivating. Fishkeeping and Waterlife, August 1958: 488-499.
Wit, H.C.D. de, 1975, Cryptocoryne alba de Wit (nov.sp.) en Cryptocoryne bogneri de Wit (nov.sp.), Het Aquarium 45(12) : 326-327.
Wit, H.C.D. de, 1990, Aquarienpflanzen, 2. Auflage, Ulmer, Stuttgart.