Sweet Fern

Pteris macilenta is a terrestrial fern characterized by a typically erect, short, and slender rhizome that supports crowded stipes ranging from 10 to 30 cm in length. The stipes are dark brown towards the paleate base and pale brown above, with dark brown, the scales are long and gradually taper to a point. This species can reach up to 50 cm in height, with its abundance of fronds dependent on the quality of the habitat, and its size can be modest as 10 cm under poor conditions. The rhizome is not deeply buried, often ascending, with lateral roots and is marked by the presence of fallen stalk bases.

The fronds of P. macilenta are pale green, membranous, and flaccid, with a broadly deltoid shape and a size ranging from 20 to 90 cm in length and 15 to 50 cm in width. They exhibit a 2–3 pinnate structure with minutely punctate laminae. Veins demonstrate anastomosing patterns, especially along the smaller branches coming off the main vein. The pinnae, which are alternate to subopposite and often long-stalked, are deltoid to ovate-lanceolate and acuminate. The rachis is smooth and yellow-brown, narrowly winged in distal half, and bears pinnae with scattered scales. The lamina texture varies from sub-coriaceous to sub-membranous in sheltered plants. Coloration ranges from dark green in shaded environments to paler green in exposed ones, with yellowing common under extreme stress. …

The genus (Pteris L.) is global presence, mainly in the tropical areas, with a few species extending southern regions to New Zealand, Tasmania, South Africa and South America. Pteris macilenta is a species endemic to New Zealand with a limited distribution.

Pteris macilenta favors soils in coastal to montane habitats, predominantly on alkaline rocks like limestone, indicating specific nutrient preferences. Found in shaded or semi-shaded environments, its distribution ranges from preferring clay slopes under karaka trees to adapting distinctively in limestone areas. Its occurrence along moisture-retaining yet well-drained sites such as riverbanks.

Pteris: a fern known to the ancient Greek, derives its name from the Greek word ‘pteron’.