DENNSTAEDTIACEAE - FERN FAMILY
Terrestrial, sometimes scandent; pantropical. Rhizomes mostly long-creeping, often siphonostelic or polystelic, bearing jointed hairs; petioles often with epipetiolar buds, usually with a gutter-shaped vascularstrand (open end adaxial); blades often large, 2–3-pinnate or more divided; indument of hairs; veins free,forked or pinnate, rarely anastomosing and then withoutincluded veinlets; sori marginal or submarginal, linear ordiscrete, indusia linear or cup-like at blade margins, or reflexed over sori; spores tetrahedral and trilete, or reniform and monolete; gametophytes green, cordate.
Smith AR & all. (2006). Dennstaedtiaceae, In: A classification for extant ferns, Taxon 55(3): 714.
The “fern family” are non-flowering and seedless plants that include mostly terrestrial and some climber species and spread worldwide. Although they have vascular systems as seen in flowering plants, they produce spores instead of seeds to reproduce.This family include the genus Pteridium Scop. (bracken) which is considered as one of the most harmful invasive weeds in the world. The Bracken is an invader of open or disturbed areas with an extensive branched rhizome, which may grow to about 400 metres (1,300 feet) in length. Because the plant competes so vigorously with other plants and the leaves contain toxic chemicals, a site where this fern becomes established is soon unfit for grazing by livestock, and the other plants can not thrive.
Anonymous 1 (2016). https://en.wikipedia.org/wiki/Dennstaedtiaceae/, Accessed date: 07.02.2016.
Anonymous 2 (2016). http://www.britannica.com/plant/Dennstaedtiaceae/,Accessed date: 07.02.2016.