the cordata group

In the current opinion, the cordata group consist of 4 varieties (Jacobsen 2002, Othman et al. 2009, Bastmeijer et al. 2010): Cryptocoryne cordata var. cordata from the Malay peninsula (W. Malaysia and the very south of Thailand), C. cordata var. siamensis with also the cultivar 'Rosanervig' from peninsula Thailand. C. cordata var. grabowskii from Borneo and C. cordata var. diderici from Sumatra. C. cordata var. zonata is interpreted as a synonym of C. cordata var. grabowskii in the Crypts pages.
Looking at the Synonyms page, it is clear that there was much debate on the taxonomical status of Cryptocoryne cordata. From C. cordata var. cordata and var. grabowskii is also known that they hybridise with C. griffithii and probably more species, making the picture rather complicated. New investigations may reveal that the status in the future will change again. The current status gives a clear geographical delimitation what is also supported by their chromosome numbers.

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C. cordata var. cordata
C. cordata var. diderici
C. cordata var. grabowskii
C. cordata var. siamensis
Broad green, cordate leaves (hand size), lower side pale green to reddish, sometimes with red veins. Normally submerged in the peat swamp. Spathe 20+ cm with a bright yellow limb.
coll. Scholler, cult. B1251
Chromosome number 2n = 34
Habitat is not well known, probably also a peat swamp. Leaves ovate. Spathe ca. 10 cm with yellow throat and a very rough, yellow to deep red limb of the spathe.
coll. Kishi09-01, cult. B1296
Chromosome number 2n = ±102
Broad green, cordate leaves (hand size), but also smaller plants exist, some forms have strong bullate leaves. Normally submerged in the peat swamp. Spathe 20+ cm with a yellow throat, often with red dots. The limb varies from bright yellow to deep red.
coll. B-06, cult. B1003
Chromosome number 2n = 68
Ovate to narrow ovate leaves, dark green to deep brown with a pale green to deep red lower side. Mostly submerged in streams on a limestone bottom. Spathe ca. 10 cm with a yellow throat and a more rough yellow limb, often with dark brown margins. C. cordata var. siamensis 'Rosanervig', a cultivar originating probably from Thailand.
coll. unknown, cult. B 17
Chromosome number 2n = 102

Reported hybrids are C. ×purpurea nothovar. purpurea, from W. Malaysia and
C. ×purpurea nothovar. borneoensis from Borneo, both with C. griffithii as the other parent.

Updated June 2014

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., T. Idei & N. Jacobsen, 2010. Notes on Cryptocoryne (Araceae) of Thailand, including a new species from Loei Province. Thai Forest Bulletin (Bot.) 38: 179-183. (Document service)
Benl, G., 1960. Ein neuer Wasserkelch aus Thailand : Cryptocoryne blassii de Wit 1960. DATZ 13 : 116-118.
Bogner, J., 1980. Tropische Wasserpflanzen am natürlichen Standort. Int.Waterplanten Symp. Ludwigia, Wageningen : 51-55.
Bogner, J. & Jacobsen, N., 1985. Eine neue Sorte : Cryptocoryne cordata Griffith 'Rosanervig'. Aqua-Planta 10(2) : 12.
Brown, N.E., 1880. On some new Aroideae. J.Linn.Soc.XVIII : 242-245, plate IV.
Bruggen, H.W.E. van, 1975. Cryptocoryne siamensis Gagnepain. Het Aquarium 46 : 90-91.
Engler, A., 1898. Beiträge zur Kenntnis der Araceae VII. Englers Bot. Jahrbuch 25 : 28.
Engler, A., 1920. (Cryptocoryne, Lagenandra in) Das Pflanzenreich IV.23.F. Araceae - Aroideae : 232-249, Leipzig.
Furtado, C.X., 1935. Araceae Malesicae. Gardens Bull.of the Straits Settlem. 8 : 145-148.
Gagnepain, F., 1941. Aracees nouvelles Indochinoises. Not.Syst. 9, 3 : 131-134.
Graaf, A.de, 1983. Sadilek over vindplaatsen van Cryptocorynen. Het Aquarium 53(2) : 51-53.
Griffith, W., 1851. Cryptocoryne. Not.Pl.Asiat.III:134-143; Icon.Pl.Asiat.3 T.170,172. Calcutta,.(Document service)
Hooker, J.D., 1893. Cryptocoryne, Lagenandra in the: Flora of British India 6 : 492-496.
Horst, K., 1981. Sind die Cryptocorynen aus Borneo für Aquarien geeignet ? I. Aqua-Planta 6(3): 59-61.
Horst, K., 1982. Sind die Cryptocorynen aus Borneo für Aquarien geeignet ? IV. Aqua-Planta 7(2): 7-11.
Horst, K., 1986. Pflanzen im Aquarium. Ulmer, Stuttgart.
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., 1985. Cryptocoryne cordata Griffith (Pflanzenportrait). Aqua-Planta 10(2): 15-18.
Jacobsen, N., 1985. The Cryptocoryne (Araceae) of Borneo. Nord.J.Bot. 5 : 31-50.
Jacobsen, N., 1986. Deterioration of the habitats of the Cryptocoryne species. Symp.Bedreiging van het aquatisch milieu, Ludwigia, Wageningen : 33 (Document service).
Jacobsen, N. & J.Bogner, 1987. Die Cryptocorynen der Malaiischen Halbinsel (4.Teil, Schluss). Aqua-Planta 12 : 96-103 (+cover).
Jacobsen, N. 2002. Der Cryptocoryne Griffith - Komplex (Araceae) in Malesien. Aqua-Planta 27 : 150-151.

Jacobsen, N. & D. Sookchaloem, 2010. Cryptocoryne in the Flora of Thailand.

Jacobsen, N. & J.D. Bastmeijer, 2014. On Cryptocoryne coradata var. siamensis. The Aquatic Gardener 27(2) : 28-39. (Document service)
Kasselmann, C., 1995. Aquarienpflanzen. Ulmer, Stuttgart.
Kettner, C., 1997. Cryptocorynen in Borneo. Aqua-Planta 22(3): 100-104.
Mansor, M., Kamaruzaman Mohd. & Adenan Jaafar, (?). A vanishing cordate Water Trumpet. Nature Malaysiana 17(3) : 99-100.
Merrill, E.D., 1921. A Bibliographic Enumeration of Bornean Plants. Journal of the Straits Branch of the Royal Asiatic Society : 106-109.
Möhlmann, F., 1978. Eine rätselhafte Cryptocoryne von Borneo. Das Aquarium 12/7 : 397-400.
Möhlmann, F., 1979. Publikation einer neue Cryptocoryne. Cryptocoryne Möhlmann 36 (spec."rosanervis"). Aqua-Planta 4(1): 3 (+cover).
Möhlmann, F., 1980. Warum gedeihen einige Cryptocoryne Arten nur schlecht oder auch gar nicht in unser Aquarium? Aqua-Planta 2-80 : 11-12 (cover).
Möhlmann, F., 1982. Cryptocorynen - Problempflanzen ? Aqua-Planta 7(1): 6-7 (cover).
Mühlberg, H., 1980. Das grosse Buch der Wasserpflanzen. Dausien, Hanau.
Othman, A.S., N. Jacobsen & M. Mansor, 2009. Cryptocoryne of peninsular Malaysia. Penerbit University Sains Malaysia, Pulau Pinang.
Rataj, K., 1974. New cultivated species of the genus Cryptocoryne (Araceae). Folia Geobot.Phytotax. 9 : 313-314, plates 15-16.
Rataj, K., 1975. Revision of the genus Cryptocoryne Fischer. Studie CSAV, c.3.Praha.
Rataj, K. & Horeman, T.J., 1977. Aquarium Plants. TFH Publ, USA.
Ridley, H.N., 1905. The Aroids of Borneo. J.Str.Br.Roy.As.Soc. 44 : 169-171.
Ridley, H.N., 1907. Cryptocoryne Fisch. Materials for a Flora of the Malayan Peninsula : 3-6.
Ridley, H.N., 1925. Cryptocoryne. Fl. Malay Pen. 5 : 86-88.
Roe, C.D., 1967. A manual of aquarium plants. Shirley aquatics Ltd.
Sadilek, V., 1973. Neue Cryptocorynen X : Cryptocoryne purpurea Ridley. DATZ 26 : 128-130.
Sadilek, V., 1974. Problemen bij de cultuur van Cryptocorynen. Het Aquarium 45(*) : 61-63.
Sadilek, V., 1979. Unklarheiten bei Cryptocoryne cordata. DATZ 32/2 : 56-58.
Sadilek, V., 1981. Sind die malayischen Cryptocorynen Problempflanzen ? Aqua-Planta 6(3): 76-78.
Sadilek, V., 1982. Unklarheiten um Cryptocoryne grabowskii und Cryptocoryne grandis. Aqua-Planta 7(1): 9-11.
Schöpfel, H., 1974. Cryptocoryne siamensis. Aquarien & Terrarien 21/10 : 338-339.
Schulze, J., 1971. Cryptocorynen aus Sarawak I-IV. DATZ 24 : 230-233, 267-270, 303-306.
Sofiman, A.S., N. Jacobsen & M. Mansor, 2008. Cryptocoryne of Peninsular Malaysia. Penerbit Universitii Sains Malaysia.
Wendt, A., 1955. Etwas über richtige und falsche Namen unserer Cryptocorynen. DATZ 8 : 236-240.
Wendt, A., 1955. Cryptocoryne cordata, grandis und griffithii. Aq.& Terr. 2(5) : 146-148.
Wendt, A., 1958. Die Gattung Cryptocoryne Fischer. Die Aquariumpflanzen in Wort und Bild (1952-1958) Stuttgart.
Wijngaarden, P.van  & H.W.E. van Bruggen, 1999. Cryptocoryne diderici de Wit. Aqua-Planta 24 : 114-117.
Wit, H.C.D.de, 1951. Cryptocoryne cordata, Cryptocoryne griffithii. Het Aquarium 22(6) : 128-129.
Wit, H.C.D.de, 1958. Cryptocoryne griffithii and its allies. Fishkeeping * (1958 ?)
Wit, H.C.D.de, 1960a. Cryptocoryne blassii de Wit sp.nov. DATZ 13(4) : 115-116.
Wit, H.C.D.de, 1960b. Het genus Cryptocoryne (13). Cryptocoryne cordata Griffith. Het Aquarium 31(3) : 50-51.V
Wit, H.C.D.de, 1961. Het genus Cryptocoryne (16), Cryptocoryne ferruginea Engler, C. gomezii Schott, C. grabowskii Engler. Het Aquarium 31(9) : 212-214.
Wit, H.C.D.de, 1970. A key to the species of Cryptocoryne Fish.ex Wydl.(Araceae). Misc.papers LH Wageningen 6 : 257-280.
Wit, H.C.D.de, 1975. Oude en nieuwe namen in Cryptocoryne. Artedi 26(1) : 112-114.
Wit, H.C.D.de, 1990. Aquarienpflanzen, 2. Auflage. Ulmer, Stuttgart.