Plate 087 · clump on a stream bank IdentificationFive marks on the plate
- 1Large, divided frond, arching from a clump.
- 2Pinnae with segments joined at the base, like a comb.
- 3Crozier unrolling; it bears brown scales.
- 4Sori in a line under the rolled segment edge.
- 5Short rhizome from which all fronds arise.
Easily confused with BrackenPteridium spp.Single fronds rising from a long creeping rhizome, in open, drier places. 087 / 100 · PLANTS · PTERIDACEAENOT EVALUATED Stream-bank brake
Pteris deflexa
Helecho de arroyo
One of the large ferns of the Tucumán montane forest. It forms clumps on stream banks and in damp ravines, with fronds that can reach 2 m. Spores form in a brown line under the rolled edge of each segment.
- Frond
- Up to c. 2 m
- Altitude in Tucumán
- 800 – 1,350 m
- Sori
- Marginal, under the edge
- Range
- Central and South America
- Ground fern
- Stream banks
- Montane forest
- Native
Altitude rangeIn the montane forest
Tucumán herbarium records Specimens with altitude data come from the Río Los Sosa, Río Cochuna and Puesto Santa Rosa, between 800 and 1,350 m. There are also records from San Javier and PN Aconquija.
EcologyWater and shade
- Moist soilstream banks and ravines
- Shadeunder the forest canopy
- Sporescarried by the wind
- Rich soilleaf litter and flood silt
Ferns have no flowers or seeds. They reproduce by spores, which need moisture to grow into a small intermediate plant.
Life cycleTwo generations
- Crozier. Each new frond starts coiled like a crozier and unrolls from base to tip.
- Marginal sori. Spores ripen under the rolled edges of the segments and are spread by the wind.
- Needs water. The spore grows into a tiny prothallus. Its gametes swim in a film of water, and a new fern grows from the union.
Where to look in Tucumán- Río Los Sosa
- PN Aconquija
- Sierra de San Javier
- Reserva Experimental Horco Molle