Having issued its first set of stamps on ferns on November 26, 2009, Chunghwa Post will issue the second set of four stamps and a souvenir sheet. The new set of stamps features “walking ferns.” The designs follow: 1. Polystichum lepidocaulon (NT$5): It has a short, erect stem and fasciculate fronds. Its laminas are lanceolate and simply pinnate, with pinnae that are falcate. Some of the rachises are prolonged and viviparous at tips. This species of fern grows on slopes in the forest understory. 2. Bolbitis heteroclita (NT$5): Its stem is short and procumbent. Its fronds are simply pinnate with dimorphic: the fertile laminas are thinner and erect, whereas the sterile laminas are more spreading. The pinna grows without a tooth in each sinus. The terminal pinnae are lanceolate, and some of them are elongated and droop downward. The tips of the pinna have adventitious buds. Either lithophytic or terrestrial, the species can be found in humus soil along streambeds in the understory of forests. 3. Adiantum malesianum (NT$10): It has a short, erect stem and fasciculate fronds. Its laminas are linear to narrow lanceolate and simply pinnate. The rachis extends to be whip-shaped tendril and has adventitious bud at tip. The pinnae are fan, obliquely triangular or obliquely oblong shaped with a pair of basal pinnae half-circular or wide fan-shaped. The species grows on slopes or cliffs at the edge of forests.4. Asplenium prolongatum (NT$25): It has a short, erect stem and fasciculate fronds. Its laminas are narrow and lanceolate and deeply bipinnatifid. A portion of the rachises are prolonged and viviparous at tip. The ultimate pinnule is linear with a singular vein. It grows in shady cliffs or on the trunks of trees in the understory of forests.