In only a few cases you can with certainty identify a Cryptocoyne only by the leaves. It helps a lot when you know from where the plants originate, but the final answer is only possible when you see the spathe (infloresecence) of the plant. Even then it may be difficult because we do not know so much about the natural variation and also because there are a lot of natural hybrids. In the aquarium hobby it is a bit easier, for most species will not grow very well and the shops offer for that reason a very restricted assortment.
Nevertheless, you can enjoy Cryptocoryne and not being sure about its name! Besides, in a few cases it is also a matter of interpretation.
Click on the picture to enlarge, click on the NAME to go to the page
This almost black leaved C. crispatula var.tonkinensiscomes from China. Up to now there are only plants of the crispatula-group identified from China. coll. Zhou 0603-1
Young leaves are rolled up in a single spiral when they appear. They have a 'convolute vernation' as it is called. In contrast to Lagenandra who has a spiral on both sides of the leaf. C. cognata coll. Yadav 0329, cult. B 625
C. hudoroi from three different localities in Kalimantan. They differ in the colouring of the leaves, both the upper and lower side. Is this a true character? coll. ME01-ME02-AM01
A cultivated specimen of C. striolata. The change in colouring of the leaves is clearly due to environmental parameters. coll. Bud-KL 0307, cult. B 1162
A very nice example of a cultivated, submerged grown C. ×purpurea nothovar.borneoensis. They are just like in nature with a deep red lower side of the leaf .... coll. TI, cult. ten Berge
photo ten Berge
... In emerged cultivation they may change their habitus and have bullated leaves with a pale green lower side.This is C. cordata var.grabowskii, a look alike. coll. B-01, cult. B 993
This C. wendtii is a popular aquariumplant sold as 'wendtii green' or so. Easy to recognise (and 3/4 of all Crypto's sold are C. wendtii so you will be right) ... coll. PB-SRL03, cult. B 1052
... But this plant is also a C. wendtii. Can you distinguish it from C. usteriana or even (a known giant) C. affinis? Probably not. coll. van den Nieuwenhuizen s.n.
photo van den Nieuwenhuizen
Four imports from Kalimantan (Indonesia) growing together emerged in a tank. Finally turned out that they represent two species. Your guess will be wrong!
The very rough surface of the leaf and its undulated margin are charactaristic for C. thwaitesii. coll. FW 02-2, cult. B 862
These nice white veins on the leaves of this C. cf. nurii are rather rare in Cryptocoryne. It is a permanent character, also seen in C. cordata var.siamensis 'Rosanervig'. coll. KN IL-19, cult.B1346
Hairs on the lower side and margin of the leaves is only known from C. fusca (picture) and from C. ferruginea. These hairs are however not always developed. coll. SW 09-12, cult.B 1321
Variation in leaf form and size in C. longicauda found growing close to each other in a peatswamp in Sarawak. photo Jacobsen
In cultivation, C. longicauda often has a narrow, fine undulated, membraneous margin on the leaves. coll. Bogner 1511, cult. B 390
Schema of the lower vegetative parts of a Cryptocoryne.
The contractible roots (with transverse rings) can pull the plant into the soil. They are not developed in all species.
The cathapyls, small reduced leaves, are often formed before
flowering, In the picture you see one just in front of the limb of the spathe, another one a bit right from it. C. waseri coll. FW 90-5, cult. B 1301
The seasonal C. nevillii shed its leaves when its habitat dries out. But also in cultivation under constant conditions, it regularly shed its leaves ...
Note the contractible roots. coll. PB08-1, cult. B 1206
... but when repotted it immediately starts growing again (note the three growth points in the picture left). You can repeat that (for ever?). coll. PB08-1, cult. B 1206
The rhizome of C. waseri is the dark, horizontal 'stem', growing to the left. Several young plants develop directly on the older part of the rhizome.This rather rare in Cryptocoryne. C. waseri coll. FW 90-5, cult. B 1301
Most Cryptocoryne make elongated subterranean stolons (also called runners) with at the end a developing young plant. C. alba coll. PB-SRL 4-4-05-01, cult B1191
Rhizome of C. crispatula var.crispatula from the Mekong river (the roots are stripped). Note the annual bulges due to the seasonal growth, As the waterlevel goes high (5+ m), the plant goes dormant and forms terete leaves.. coll TI , photo Idei
C. retrospiralis is a seasonal plant, like C. crispatula var. crispatula, and shed its leaves when the waterlevel rises. They form terete (chives like) leaves. In cultivation, their 'clock' keeps running on time, regardless the waterlevel! Note also the small, upwards growing roots emerging from the soil. coll. Bogner, cult. B 1055
C. ciliata var.ciliata makes long overground, firmly attached runners, not seen in other species. coll. SW 0601, cult B 1161
C. ciliata var.latifolia makes short, upright 'runners' that easily break off and will root at some place. Also unique in Cryptocoryne. coll. NJT 02-27, cult.B889
In C. elliptica a growth point remains attached to the leaf when broken off. A young plant develops from there. coll. NJM 04-26, cult. W 201
photo van Wijngaarden
In C. sivadasanii is something alike, but here the growth point remains attached to the root. drawing Sivadasan
The leaves - of course - help you to identify a Cryptocoryne. You can narrow your search to a small group of candidates. Often you have a group of characters, difficult to explain how they relate and to write it down. Without experience in cultivating the plants, it is always difficult.