Kingdom – Plantae and Animalia Kingdom : Plantae of Plant Kingdom -
Division : Thallophyta (Algae) -
The plants in this divisions are commonly called
algae. The terms “Algae ” was coined by C. Linnaeus which means ‘sea weeds’. The division is characterized by the following :
The division comprises of most primitive and simple plants not differentiated into true roots, true stem and true leaves. Therefore, they are
thalloid (thallus-like) and placed under the division-
thallophyta.
They are predominatly aquatic, occur both in marine (sea water) as well as fresh water habitats. However, some are terrestrial and grow in moist places.
Algal cells possess photosynthesis. Thus, the algae are photoautotrophs.
Some algae have additional accessory pigments of other colours (such as red, brown, yellow, etc.) and accordingly they have beeen classified into different groups. such as green algae, red algae, brown algae etc.).
The plants are thalloid (figure). The plant body may be unicellular (Chlamydomonas, Chlorella), colonial (Volvox, Hydrodictyon), filamentous unbranched (Spirogyra, Ulothrix), filamentous branched (Chara, Cladophora), heterotrichous (Ectocarpus) or foliaceous (Laminaria, Ulva, Fucus, Sargassum).
The reproductive organs are unicellular non-jacketed gametangia. The contents of reproductive structure are completely converted into spores or gametes.
After fertilization, embryo is not formed.