THE CUCKOO-PINT’S TRAP FOR UNWARY VISITORS

THE Wild Arum, known to country-bred children as ‘Lords-and-Ladies ‘or ‘Cuckoo-pint,’ introduces us to a kind of bloom, or inflorescence, which is also a trap. Superficially, it consists of a central club-like ‘spadix ‘enveloped by a large, leaf-like bract, or ‘spathe.’ If we tear open the spathe, we disclose the ‘lords-and-ladies ‘clustered round the lower part of the spadix. These are really the Arum’s simple flowers. Checking them off from above downwards, we find (I) abortive, hair-like flowers not directly connected with reproduction, (2) four-lobed anthers, or male flowers, and (3) female or seed-producing flowers, each with a single pistil.

Insects, especially tiny midges, are attracted by the purple club of the spadix and its carrion-like odour. They creep down into the chambered part of the spathe, where the flowers are—the hair-like ones allowing them to creep in, but preventing their return. The female flowers mature first, and are thus ready to receive any pollen that the midges bring with them from another Arum. Later, the anthers of the male flowers mature, and scatter their pollen over the prisoners. In the end, the abortive hair-like flowers shrivel up, thus allowing the captives to make good their escape; but not before they have been pressed into the service of the plant as carriers of its pollen to other blooms of the species.

In the Dog Rose we have a fairly simple flower of the five-petal type, not unlike the buttercup in its general arrangement. Inside the circle of stamens there is a swollen rim which looks like a nectary, though it secretes little if any nectar. The flower, however, is visited by many insects—chiefly bees, beetles and flies—which come to collect or feed on the pollen. The bees, of course, carry their spoils home to their hives or nests, whereas the flies and beetles eat it on the spot. The stamens and stigmas mature at the same time, so that either self- or cross-pollination may result from these activities.

Since, however, the centre of the flower, with its group of closely set stigmas, is the most convenient alighting place, an insect dusted with pollen brought from another rose is likely to effect cross-pollination at its first arrival.

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