Of roses and buttercups

Press, 2 August 1985, Page 14

Of roses and buttercups

August is the month of the winter roses — species and hybrids belonging to the genus Helleborus. The earliest of them, the waxen white Helleborus niger, a European native, is already past its prime, and its pristine flowers have lost their waxy glow and are rapidly fading to a wan pink; but they will persist for a long time yet. This is a first-rate garden plant. Although it is not as often seen in New Zealand gardens as the coarser Helleborus orientalis hybrids, it is very easy to grow in either sun or shade provided it has the well-drained, leafy soil that it loves. As with all members of the genus, its flowering period may extend over several weeks, or even months because different clones may flower at different times. Even longer is the flowering period of Helleborus foetidus, a distinctive shrubby plant with leaves deeply divided into fingers. Its flowers begin to open in May; the calyces are green, with a maroon rim, and they persist long after the seeds have ripened and been shed, so that the plant remains highly decorous from May until September and sometimes October. Each stem which has flowered dies afterwards, and new stems grow from the base each year during the life of the plant, which is usually three or four years. As it seeds freely, replacements are seldom scarce. Helleborus foetidus is seldom seen in nurseries, but it is the sort of plant that is often exchanged among gardeners. Two forms are grown in

New Zealand, one with dark, dull green leaves and one with lighter green leaves and a maroon-red band at the base of each segment. The latter is the better garden plant. Also green-flowered are H. corsicus, sometimes called H. lividus, and its more vigorous form, H. sternii, a “hybrid” between two subspecies in the group. These re larger plants (I have had them up to a metre high but usually only half that) and are of similar semi-shrubby habit, sending up new shoots from the base each summer to replace the spent flowering stems. They live longer than H. foetidus but young plants produce the most and best flowers. The old ones are best culled after a few years, and replaced with some of the many seedlings which come up around them if they are happy. A New Zealand-raised plant called “White Magic”

may well be a hybrid of one of this group with H. niger — a cross which has been made in England to produce a hybrid named H. “Nigricors.” Helleborus niger and the H. orientalis group will live for many years without any noticeable deterioration in their flower power. As they are herbaceous, they may be propagated by division immediately after flowering, but if the summer after transplanting is dry they may not flower for a year or two. Helleborus orientalis is not a single species, but a group name for garden hy-

brids raised from about half a dozen Eastern European and Western Asian plants. They come in a wide range of colours from a lovely greenish white (derived from H. olympicum) to deep claret rose, and many have purple or maroon stippling and spotting, inherited from H. guttatus and H. abchasicus, on the interior of the flowers. H. guttatus has a lovely white form, speckled with reddish crimson, which is one of the few in this group to come reasonably true from garden seed. Why are they called “winter roses?” Frankly, I don’t know. They don’t have any botanical connection with roses because they belong to the ranunculus family — along with buttercups, clematis, and delphiniums. A similar name problem occurs with one of the buttercups, which is already

flowering. This is Ranunculus ficaria, which comes in both large and small forms that don’t, to the lay eye, appear to belong to the same species. The larger form has bold, round leaves and bright, dandelion-yellow flowers, and has escaped from cultivation to naturalise in a few places. It is difficult to eradicate, because it will grow again from small pieces of root left in the ground. The large variety is seldom deliberately cultivated in New Zealand, but several different varieties are grown of the small form, with double or single flowers which range from near-white to coppery orange. None of these is what you could call a weed, but they will spread round a garden, coming up in unexpected places, because wind and birds disperse the tiny, wheat-grain tubers that form each season at the base of the dying leaves. Gardeners call this buttercup the “lesser celandine” — a confusing appellation because the “greater celandine” (which flowers in summer and isn’t very much bigger than the major forms of the lesser celandine) is not a buttercup at all, but a poppy. The only real thing they have in common is the colour of the flowers. The greater celandine has glaucous leaves wUch, when damaged, exude acrid, bright orange sap; at one time this was used as a cure for warts. An alternative name for the lesser celandine — pilewort — indicates unambiguously the affliction for which it was regarded as a cure.

Oardener’s W DIARY

Derrick Rooney