As part of the University of Reading MSc Plant Diversity and MSc SISS students make a collection of lower plants (lichens, mosses and liverworts). Often the campus provides a useful source of material and this year is no exception! Amongst this years new and interesting finds on campus is the Balloonwort (Sphaerocarpos spp.). This tiny plant is a liverwort notable for the tiny disc-like thallus which bears the apple-green balloon-like structures which conceal the sex organs. The picture here is magnified and each balloon-structure is only a millimeter across, tiny indeed!
The Balloonwort grows on bare soil and waste ground, and female plants grow to about 2 cm across on a good day and so Liew Pei Shi, the student who discovered it growing near the ICMA Building, must be congratulated for her keen eyed search! This species is a winter annual which means it grows from autumn through winter and dies back in the spring. Liew collected this plant in February and, as the picture shows, it was already beginning to die back then (witness the dirty brown balloons in the picture!) so it will be pretty tough to find it again now until the autumn. But Dr M will be lying in wait, as it is a rather rare plant and often overlooked due to its diminutive size. The Balloonwort is is a new record for the campus as far as we know, and so this is a very nice discovery coinciding as it does with the Bioblitz being held on campus this weekend!