Marchantia polymorpha L.

Description

Marchantia polymorpha is a thalloid liverwort forming flat, green, ribbon-like patches on moist soil, rocks, walls, and shaded habitats. Unlike vascular plants, it lacks true roots, stems, and leaves. The dominant plant body is the gametophyte, which is a dorsiventral, dichotomously branched thallus. The thallus is usually 2–10 cm long and 1–2 cm wide, flattened, leathery, and dark green. The upper surface is divided into polygonal areas called air chambers, each containing a central pore that allows gas exchange. The lower surface bears rhizoids and multicellular scales that help in attachment and water absorption. Vegetative reproduction occurs through gemma cups, which are small cup-shaped structures present on the dorsal surface of the thallus. These cups contain lens-shaped gemmae, which detach during rainfall and develop into new plants. Reproductive structures are borne on specialized stalks. The species is dioecious, with male and female reproductive organs occurring on separate thalli. Male plants produce antheridiophores, which are stalked umbrella-like structures bearing antheridia on the upper surface. Female plants produce archegoniophores, which are also stalked umbrella-like structures with radiating lobes where archegonia develop. After fertilization, the sporophyte develops beneath the female umbrella. It consists of: Foot Seta Capsule The capsule produces numerous haploid spores and elaters. Elaters are hygroscopic structures that assist in spore dispersal.

Diagnostic Characters

Distribution

Where it grows on campus