Isoetes histrix Bory
Family: ISOETACEAE
Genus: Isoetes
Province distribution: Balearic Islands. Girona.
Distribution in the islands: Mallorca. Menorca.
General distribution (Phytogeography): Holoartica
IUCN Category: Endangered
Flowering time: JanFebMarAprMayJunJulAugSepOctNovDec
Life-forms: Geophyte.
Habitats: Non-saline wetlands (intermittent watercourses, streams, artesian wells, ditches). Ponds on siliceous substrates.
Characteristics: A small plant without visible stems forms a leaf rosette with linear leaves that grow prostrate along the ground; underground forms a small trunk from which emerge the roots and roots. Given that this is a terraphyte, it forms no kind of flower, at the leaf base forms a sort of small cavities in which the sporangium can be found. Identification has to be observing the resulting spores, which for these species are spinulate. This character permits it to be differentiated from Isoetes duriei, which is morphologically similar, but has alveolate spores (the Isoetes have two spore types, this character refers to the female spores, which are large, up to 0,8 mm, and such can be seen by the naked eye). Lives in wet areas on substrates absent in carbonates.