This wonderful orchid flowers every July and transports me to the mountains of Costa Rica and the 2005 school expedition to the forests of Poas Volcano.

Prosthechea brassavolae is an impressive species, and one of our real favourites, with 40cm bulbs topped with two 50cm leaves, and the 80cm flower spike carries up to 30 large flowers.

We found Prosthechea brassavolae to be the most common large flowered orchid in the Bosque de Paz reserve in central Costa Rica. The habitat is wet evergreen forest at 1400m with lush epiphytic growth of ferns, bromeliads and orchids (our photo of the reserve below) on large evergreen trees. Prosthechea brassavolae grew mainly on the lower branches of the large trees competing with the other epiphytes and holding its flowers clear of the foliage to attract its pollinator.

The species is fragrant at night and probably pollinated by moths. In 2005, two A level science students tried to camp out at night by one of the flowering plants of Prosthechea brassavolae to try and photograph the moth in question. However the rain forest can be a bit spooky at night, and in Costa Rica is full of the sounds of exotic animals so the sixth formers lasted less than an hour before returning to the comfort of a hammock at the lodge. Perhaps we will have another try sometime.

Not surprisingly, given the habitat, the species enjoys cool temperatures, shade and lots of water. We have found that in common with other orchids from cool wet forests (Masdevallias and Draculas in particular) plants can suffer heat stress if too dry in hot weather resulting in black spotting of the soft green leaves and this week we are working hard to keep plants damp at their roots so that they can keep cool in this hot weather.