Once species in their own right, current consensus (2018) seems to be they're all C. minima. Regardless, they represent distinct and recognizable morphotypes and are still useful names. Perhaps they should be considered a subspecies.
Jan Basteimeijr writes:
"In 1979, Wim de Wilde and Brigitta Duyfjes collected a new Cryptocoryne in the Leuser Reserve in northern Sumatra with strongly bullated leaves. Because there wasn't an inflorescence, many growers were involved to get this plant into flower. Robert A. Gasser was the first who succeed. His plant was the basis for the description by De Wit and Jacobsen (de Wit 1983) as C. amicorum, the 'Crypt of the friends'. Soon it turned out that other plants from the same collection could have a yellowish to purple limb of the spathe. A second collection in 1991 gave the same variation, however the original red striped limb is never seen again."
Jan Basteimeijr writes:
"Robert A.Gasser (Florida, USA), a very good Cryptocoryne grower, got plants imported from Sumatra. There was no information on the exact locality. They were shipped together with C. scurrilis from central Sumatra. This plant flowers with a distinct yellow limb of the spathe. The margins of the limb are rather denticulate (the picture above is unique for it is the only picture of the type material). This plant is described as C. gasseri (Jacobsen 1979). This plant has also very bullate leaves..."
Cryptocoryne minima is well known from Penang and Kedah in West Malaysia. Plants were regularly imported into Western Europe from the 60's. See for example the catalogue from Shirley Aquatics UK (Roe 1967). In 1971 De Wit described a new species as C. zewaldiae which originates probably from West Malaysia. This plant is a bit taller than - the until that time known - C. minima. He named the plant after Ike Zewald, the artist who made the drawings at the institute in Wageningen (see the botanical link to WAG). In his book there is a picture and a drawing (de Wit 1971, 1990).
