Eranthis longistipitata - plant of the month March 2012
The genus Eranthis is a member of the Ranunculaceae, the Ranunculus family. It comprises(arguably) eight species with a natural distribution from western Europe, east across Asia to Japan. They are perennial plants with tuberous rhizomes and favour mainly woodland or rocky scrub land. The commonly available E. hyemalis forms drifts of yellow when naturalised on the rock garden, in woodlands or under deciduous shrubs. The genus is represented in many collections by the fine cultivar E. x tubergenii 'Guinea Gold' (shown), a hybrid between E. cilicicus and E. hyemalis.
Eranthis longistipitata has a general distribution from central southern USSR eastwards as far as the Tian Shan and Pamir Alai where it is often seen pushing up through cool rock crevices. It has proven tricky in cultivation, requiring bulb frame or pot culture in an alpine house to do well. It comes quite easily from freshly sown seed but takes a relatively long time to reach what would approximate flower size; this is far from guaranteed and may elude even the most accomplished grower. Propagation by division is possible but further delays the potential for flowering as, once set, the knobbly rhizome is best left undisturbed for a number of years, with frequent feeding during the short growing season.
A relatively long stem leads up to the whirl of much-dissected bract leaves, looking like an Elizabethan ruff between the base and the stalked flower; the name 'longistipitata' comes from the fact that the seed pods are held on long stalks (stipes) rather than being sessile as in the other species. After flowering (if you're fortunate!) the seed is formed and shed fairly quickly, the whole plant then fades quitely away underground for the rest of the year, an adaptation to its natural growing environment where the suitable growing season is short.
Eranthis longistipitata is arguably the least horticulturally attractive species within the genus, with smallish flowers when compared with the other 'yellows' though the clone shown is one grown at Gothenburg under the accession number '1984-0696p W Prasil' and is an exceptionally fine form.