First things first. "Pink Eumorpha" is not a legitimate hybrid name, since hybrid names cannot include species names or imply that they are a variety of a species. The 1988 Sinningia Register has an entry for this plant, showing that its first listing was in a 1963 Kartuz catalog. The entry is followed by the dread word "coderejected".
Despite its unknown origin and nomenclatural disgrace, the plant is still attractive and easy to grow, definitely easier than its putative species relative. It produces lots more flowers than Sinningia eumorpha, and while most people would prefer the pure white-flowered eumorpha to either "Pink Eumorpha" or the lavender-tinged eumorpha, I much prefer the flowers of "Pink Eumorpha" to any eumorpha with lavender in it.
Actually, apart from the green leaves and the name, there isn't all that much to connect "Pink Eumorpha" with S. eumorpha. "Pink Eumorpha" has also been compared with S. 'Anne Crowley', but they are clearly not the same. The following table compares the three varieties.
|Attribute||"Pink Eumorpha"||S. eumorpha||S. 'Anne Crowley'|
|Leaf color and texture||Light green, thin||Dark green, thin||Green, robust|
|Color of petioles and leafbacks||No trace of red on petioles or leafbacks||Usually with red petioles and some red on leafbacks||No trace of red on petioles or leafbacks|
|Flower color||Pink||White or lavender, with yellow central stripe||Pink, hairy and darker on outside|
|Calyx lobes||Spreading (see picture above)||Spreading||Clasping flower tube|
|Inflorescence||Multi-flowered axillary cymes with peduncles||Axillary cymes, almost always of just one flower||Multi-flowered axillary cymes with peduncles, from the top nodes|
This picture shows the flowers of S. eumorpha and S. "Pink Eumorpha" side by side.
See a picture of the tuber of S. "Pink Eumorpha".
|Leaves||Green, with no trace of red on petioles or leafbacks|
|Dormancy||Stems fully deciduous. Dormancy appears to be obligate.|
|Season||Blooms in summer|
|Inflorescence||Axillary cyme, with several flowers and a well-defined peduncle|
|Hardiness||Has survived 28F (-2C) in my yard|