Pouzolzia taiwaniana (Urticaceae), a new species from Taiwan

Pouzolzia taiwaniana, a new species from southern Taiwan, is described and illustrated. Somatic chromosome number (2n = 28) is here reported. Pouzolzia taiwaniana resembles P tuberosa Wight in having tuberous roots, but differing in being a much smaller plant, usually less than 30 cm (vs. 30-180 cm) long, leaves 1-2 cm (vs. 2.5-7.5 cm) long, cordate or broadly ovate (vs. elliptic-lanceolate), basal lateral veins reaching the middle part of leaf margin (vs. reaching leaf apex). Pouzolzia taiwaniana was first discovered in a forested watershed area in 1990. It then comprised only a handful of individuals on a moist shady rocky slope. Unfortunately, the habitat was subsequently destroyed by landslides accompanying typhoons that hit Taiwan. In 2011 it was rediscovered in a landscape reserve 30 km south of where it was first collected. Pouzolzia taiwaniana is endemic to Taiwan. The only known extant population is on a mudstone slope that is prone to erosion and landslides. The area of distribution is approximately 50 x 10 m(2) and contains less than 100 plants. According to IUCN Red List criteria, P. taiwaniana is considered to be Critically Endangered.