Pterocystis pulchra (Dürrschmidt,1987 ) Siemensma, 1991
Diagnosis: Periplast, 20-30 µm. in diameter covered with 2 types of scales. Plate-scales, 3.0-3.3 x 1.7-2.0 µm, are ovoid to ellipsoidal or sometimes asymmetrical. They are thin with deeply concave middle parts, elevated submarginal parts and slightly inflexed margins. They are patternless, the central ridge indicated only as a slightly darker line. The spine-scales are rather numerous, 3.0-4.0 µm long, max. 3.1-3.8 µm broad, of almost funnel- or calyx-like appearance. The shaft is reduced to a dark narrow ridge, probably hollow, because of its less dense centre. The lateral wings are continued along the whole length of the shaft, reaching their maximum breadth in the middle distance of the scale. From here towards the proximal end they are closely anchylosed with the basal wing and, after considerable narrowing, form a patternless hollow stalk, which can be long and slender or short and stumpy, Distally the scales are of differing lengths; commonly the front parts are shorter and slightly curved outwards, and the rear parts straighter, reaching their max. length near the distal shaft end. The lateral wings are ornamented by thin delicate ribs, which run from the shaft to the outer margin transversally or obliquely. Ribs are also present on the front part of the calyx but here they run inwards from the outer margin.
Ecology: Type habitat: Swamp on the left-hand side of the southbound Pan American Highway, 42 km south of Puerto Montt, (1981)