A feast of decorative flowers

Press, 26 November 1982, Page 14

A feast of decorative flowers

Oardenersl W DIARY

Derrick Rooney

When Britain was desperate for food crops during World War II the British Ministry of Food commissioned Dr W. T. Stearn, a noted horticulturist, to study the onion family for alternative crops.

Reporting years later in a “Lily Yearbook” on his experiments, Dr Stearn wrote that all the allium species proved to be edible, with the exception of Allium sioulum, which tasted “like a gas escape.” Nowadays this plant, which has been separated from the rest of the alliums and put in its own genus as Nectaroscordum siculum, is so rare in cultivation that I doubt if any of its owners would want to eat it, even if it didn’t taste like a gas escape. And now that I have seen my plant in flower (I raised it from seed and have been waiting five or six years for the Big Event) I am baffled. Why hasn’t a bulb of such extraordinarily subtle beauty become more widely known? Nectaroscordum siculum has the same refinement and

grace as many of the fritillarias, the connoisseur’s bulbs in the lily family to which it is distantly related.

Its colours, are superficially dull, and their richness becomes apparent only when the flower is closely examined. Like most of the onions, Nectaroscordum siculum is a robust-growing plant with 1 umbels of bell-shaped flowers. Only very minor differences separate it from the “true” onions, the main one being that its tepals (the petal-like bits of the flower) have three to five central veins, whereas the alliums have only one. Its foliage emerges early, often in winter, and has usually shrivelled away by flowering time in midNovember. When the flowers, which are in a ring around the top of the stem, are open they are pendent, but once they are pollinated they begin to rise, and the stems begin to straighten. By the time the flowers have faded the stems are pointing straight up and are topped by immature seed-

pods, like little skyrockets. The leaves are pale green and quite thick, with a pronounced keel. The flower-colours vary from greenish-white to apple green, flushed with maroonred. Tip up a fresh flower and you will see inside it an intricate colour pattern — also the three oval, glistening green nectaries from which its name comes. ii

Nectaroscordum siculum is a native of Southern and South-eastern Europe, with its westernmost populations in the south of France. The best forms, the reddish or maroon-flushed ones, come from the eastern end of its range.

Another onion which has begun flowering this week, just in time to help fill the November gap between the

last of the spring and the first of the summer flowers, is Allium christophii. This is another plant which has suffered from a recent change of name. It used to be called Allium albopilosum, and is still listed as such in many catalogues (one specialist society’s seed list last year had both names — as separate lots.) • But under the rule of priority its valid name is now determined to be Allium christophii. The bulb comes from northern Iran and Soviet Central Asia, and has an enormous steely-mauve head, like a helmet full of shooting stars. My experience of this bulb is that it grows best in rich, even heavy soil; clumps slowly fade away in my thin, hungry soil, whereas in my previous garden, it grew like a weed in the heavy, claybased loam.

I am at a loss to explain this, because other plants and bulbs from Soviet Central Asia now thrive for me, and if collector’s field descriptions are to be believed, a heavy, wet soil is the opposite of what this bulb

In the wild it grows on parched, stony hillsides, where it must be a remarkable sight. If you have a clump you can save yourself some Christmas money, because a dried seed-head, either in its natural bleached-bone colour or dipped in silver paint, makes a splendid decoration for the top of a tree. Even more odd is a plant which has mushroomed into flower on the rock garden — just in time to be battered into insensibility by the nor’wester that blew all last week, and is now blowing again. This is Roscoea humeana, a hardy relative from Szechuan and Yunnan to the tropical ginger plant. It rises late and retires early, and is in full flower, in early summer within a week of its emergence from the ground. When out of flower it looks like sweet corn — one garden visitor last summer asked me why I had corn in the rock garden. In flower it is spectacular. Imagine a cross between an iris and a tropical orchid, and you have Roscoea humeana. The colour is rich rosy purple. i Several other roscoeas are in cultivation. The bestknown is R. purpurea, from western China, a robust plant

which is much taller than R. humeana at flowering time, but does not flower until late summer and is a bit tricky to grow, because it must have a cool, moist spot but is apt to rot off if too wet in the winter.

I should have two plants ofthis roscoea, but, as often happens, I have forgotten where I put them. I will have to wait until they have had time to make their presence felt before I know whether I still have them. Yesterday I noticed that a closely related species, Roscoea procera, is just poking a leaf through the ground. This is a more robust plant than the other but is seldom grown true to name. If it is the “real” Roscoea procera it will have white flowers, with a purple lip, but so far it shows no sign of attaining flowering size. A fourth species is Roscosa alpina, from Kashmir'. This flowered last year and the previous year, but so far this season has not made an appearance, that does not necessarily mean it is dead, because it has in the past lain dorment until the end of November, though it is usually well up by the middle of the month.

If I have lost it I shall not mourn for long, because in flower it is the least effective of the species.