Plant Biology Conservatory (University of Illinois Urbana-Champaign)

According to a 2018 post by Illinois Extension, the University of Illinois Plant Biology Greenhouses were built in 1988 to provide research and teaching space. By 1991 the conservatory's 2,000-square-foot tropical landscape, now open to the public, was complete. The Spanish edition of Wikipedia adds that the facility was created to supply living plants to the Department of Plant Biology; the current official site ties it to the School of Integrative Biology and to users from the LAS and ACES colleges, with the conservatory and collections sitting alongside the research wings.

The place long stayed quiet. Wikipedia reports that a 2005 Daily Illini article, headed "Secret garden", noted few visitors because many people did not know it was open to the public. In 2023 the university counted about ten visitors a day, more on group tours. That year student staff began labelling the plants, with QR codes planned, lighting was moving gradually to LEDs, and beneficial insects had cut the use of insecticide. A titan arum that had flowered in 2011 was still alive.

The conservatory is the publicly open part of the Plant Sciences Laboratory complex, which the official site describes as three wings of research greenhouses. Its main room is a very tall greenhouse, rising to 37 feet (about 11 m) according to Illinois Extension and a local visitor guide; the Extension writer remarks on the warmth beneath the glass roof. A 2003 photograph on Wikimedia Commons shows, above the foliage, tall glazed walls divided into large panes and, higher up, a glazed roof on a slender frame.

The room covers about 2,000 square feet (190 m²). A small stone path circles it, an island of tropical foliage fills the centre, and a bench near the entrance looks over a water feature. A corridor then serves eight smaller rooms, about 1,600 square feet (150 m²) in all, given over to specialised collections: these are working rooms where students catalogue the plants and monitor variables. Temperature sensors in each room alert staff to extremes. In 2023 part of the greenhouse lighting was already LED and the rest high-intensity discharge, with the full conversion announced for the end of summer.

The 2018 Illinois Extension post counts more than 1,000 species from more than 150 families; the university (2023) and Wikipedia (as of 2012) give more than 200 species and about 60 families of tropical and subtropical plants, chosen for botanical interest or economic importance. The largest room houses cycads, seven species of them according to the Extension. A cacti and succulents room shows a tree-form Opuntia; another, devoted to carnivorous plants, holds sundews and pitcher plants, kept near the floor to catch insects active at night. The 2018 post also mentions a "Jurassic Plants" collection and a "Wicked Plants" room.

Useful plants include cacao and coffee, plants that yield pineapple, vanilla, cinnamon, cardamom, mandarin oranges and cassava, and a banana plant. Epiphytes include orchids, philodendrons and Spanish moss. Wikipedia lists Brighamia insignis, Lebronnecia kokioides and Sauromatum venosum as plants of special interest; the university adds Aristolochia macroura. A sensitive plant may be touched when a sign allows it. Wikipedia also records an outdoor butterfly garden.

The conservatory stands at 1201 South Dorner Drive in Urbana, on the University of Illinois campus. Entry is free, with no front desk or ticketing: visitors simply walk in. It is open on weekdays only and stays closed at weekends, on holidays and on campus-designated holidays; class tours, events and some work can limit access, and the greenhouse's Instagram account announces closures.

It is a teaching and research site, so visitors stay on the walkways and touch plants only where a sign allows. Metered parking runs along Dorner Drive, where a space is usually easy to find. The modest size of the greenhouse and its eight side rooms makes for a short stop, which press and Extension writers present as a tropical interlude in the depths of winter. Educational tours for groups can be booked in advance.