by Ian Brand

Wharfedale Naturalists Society

I HAVE just booked our summer holiday. Environmentally friendly and UK based, involving no stressful trip to the airport. The food will be just like home cooking. Any guesses? It’s going to be beautiful Wharfedale this year!

Fortunately, I am not going to be missing out on the exotic. Now is just the right time to marvel at one of our most interesting native plants. Most of the members of the Arum family (Araceae) grow in the tropics and sub-tropics but we have our very own example growing right here, Arum maculatum. You probably know it as Lords-and-Ladies, Cuckoo Pint, Jack-in-the-Pulpit or one of the many other evocative regional names, often of a suggestive nature.

Growing in woods and shady hedge banks, Arum maculatum is unmistakeable with its shiny dark green arrow-shaped leaves arising in early spring. These are followed by the distinctive ‘flower’ from April to early June and poisonous red berries come late summer.

It is the ‘flower’ structure and mechanism of pollination that makes this plant so fascinating. A large leaf-like hood or cowl known as a spathe surrounds the upright chocolate-brown pencil-shaped spadix. The numerous tiny, petal-less flowers are hidden from sight at the base of the spadix. The female flowers are clustered together at the base, the male flowers above with a ring of male sterile flowers at the top with bristle-like hairs. This allows insects to enter but not escape, just like a crab or lobster pot.

Together the spathe and spadix form a highly specialised structure, which acts as a pitfall trap. Insects, especially owl-midges, are attracted to the spadix by its foetid odour and higher temperature compared to the surroundings. When insects land on the spadix or inner surface of the spathe (both smooth and slippery), they lose their grip and fall through the ring of bristles. This traps them in the bottom of the pit, where the female flowers are already mature, thereby getting dusted with any pollen the midges maybe carrying from another plant. After pollination, the female stigmas soon wither, leaving the now mature male flowers which in turn deposit their pollen on the trapped insects. In the final stage of this clever process, the entrapping bristles shrivel and drop, allowing the insects to fly off and pollinate another plant.

It is truly amazing and all on our doorsteps; you don’t have to go far to meet the exotic!

www-wharfedale-nats.org.uk