Description
The flower is held on a pedicel of 9-30mm length and is a large conical trumpet up to 45mm across at the mouth, in our largest specimens. In our plants the trumpet is a pleasing, wide cone (and not narrowly flared as in forms of some bulbocodium). The flowers of our stock are an intense, well-coloured shade of rich, sulphur or citron yellow, the form which is considered typical as N.b. citrinus is never deep, dark gold, it is a paler citron-sulphur shade. The stamens are held usually (but not invariably, as you can see in one of our photographs) within the confines of the corona, with the upturned style protruding beyond these, though usually this stays within a few mm either way of the line of the corona. The tepals are quite narrow and are sulphur- or citron-yellow with a greenish yellow base. They are shorter than the corona though they can still reach 20mm long by 5mm wide.
This has flowers in which the diameter of the corona is slightly less than the diameter of those of its closest relative, N. b. validus. This does not actually mean that the flowers are smaller, they are not, in fact the flower is longer and the shape of the trumpet means that the volume of the flower of N. b. citrinus is actually greater. Both substantially exceed the usual size of ordinary, trade, subsp. bulbocodium.
This has deep green leaves about 3mm in diameter, which can reach up to 25cm long, depending on conditions. These are both shorter and narrower than its nearest relative N. b. validus.
The area of distribution in the wild lies to the mountains north of that for N. b. validus and as such it is found at slightly lower altitudes as these mountains trend down, eventually, to sea level on the Bay of Biscay.
In cultivation this is a wonderful and distinct form which makes its large flowers in February here. It is one of our largest flowered forms. The flowers initially sit quite low and this makes them seem even larger, then, slowly the flower stem lengthens and brings them right into view. Cultivation is best in well-drained compost in a frame or alpine house which lets you seen the flowers unspoiled early in the year, from February into March. If grown in pots we find this does NOT like too severe a summer rest and plants are best stood out from under glass after seed has ripened. Do not forget to look after them though, if you want the best results for the next year. In the garden it will be later to flower and can perhaps be left in for a number of years, before lifting to divide. A sunny, raised bed would suffice with the plants growing in a fertile, well-drained, loam-based compost.
Raised from seed of cultivated Rafael Diez plants.
Introduced to our lists March 2021
