A gnarled vine snaking up the trunk of a host tree represents a success story for the Jawaharlal Nehru Tropical Botanic Garden and Research Institute at Palode near here. The creeper, belonging to the Coscinium fenestratum species, a key ingredient in over 60 Ayurvedic preparations for various ailments including eye diseases, is brought back from the brink of extinction.

Time was running out for it till 1984 when the institute took up an ambitious conservation project for the species, confined to its natural habitat in the interior forest and endangered by over-exploitation. After several attempts, scientists managed to germinate seeds of the climber, known as maramanjal (tree turmeric) in local parlance for the dark yellow flesh of its stem. Today, the institute regularly supplies saplings of the species to the Forest Department for reintroduction into the wild.

The 27-year-old climber is just one of the attractions in the sprawling 300-acre campus that is home to a bewildering diversity of flora. For five days from Tuesday, the institute is keeping its doors open to the public, under an outreach programme to showcase its rich biological wealth and its research achievements.

On Wednesday morning, the normally silent campus was abuzz with activity as hundreds of children from several schools streamed in, along with college students, researchers, teachers, nature lovers, and families including senior citizens.

From the largest collection of bamboos in India, to a carefully recreated homestead medicinal plant garden, giant water lilies floating in a pond, rare orchids, palms, ferns, trees, and tissue culture plants, the Open House had something to capture the interest of every visitor. Everyone of the over 4,000 species on display had name boards for identification.

Stalls exhibiting the research activities and achievements of the various divisions at the institute witnessed a heavy rush. An art and photo exhibition and display of different types of thatching, traditional farming equipment such as yoke, plough and paddle, fish trap, coconut leaf baskets, vetiver fans, wooden boxes, combs, kitchen utensils, and bamboo ladders were the major attractions.

Collection of seeds is another highlight of the event. The double-coconut seed weighing up to 17 kg that is endemic to the Seychelles and the wild durian (Cullenia exarillata) eaten by the lion-tailed macaque inhabiting the Silent Valley forest were instant hits with students.

Another interesting highlight is the lady's slipper orchid, a variety that was believed to be extinct until it was rediscovered in the early 90s. The institute is engaged in efforts to propagate the species and reintroduce it in the wild. The traditional homestead medicinal plant garden with its emphasis on conservation education is also a big draw.

Visitors thronged the grounds to see various species of carnivorous plants and the country's richest collection of 68 bamboo species. The sales counter set up on the campus sold ornamental plants, fruit tree saplings, and medicinal herbs worth over Rs.20,000 on Tuesday.

Institute director P.G. Latha said the Open House would be made an annual event from next year and organised on November 14 to coincide with Children's Day. She said 25 women farmers had been indentified for training in mushroom cultivation and processing as part of a scheme to be implemented in collaboration with the National Bank for Agriculture and Rural Development (NABARD).

Deputy director S. Rajasekharan said the Open House was designed to supplement classroom education by exposing students to the wonders of nature and help them develop an interest in biological sciences.

Speaker G. Karthikeyan inaugurated the Open House on Wednesday. V.N. Rajasekharan Pillai, Executive Vice- President of the Kerala State Council for Science, Technology and Environment, and K.C. Shashidhar, Chief General Manager, NABARD were present at the function.

The Open House goes on up to Saturday. Entry is free.