Number of species in the collection: 1.
Pictures of Anthocerotophyta:
Characteristics of Anthocerotophyta:
The Anthocerotophyta (which means plant with flower-like horns) are non-flowering
plants with spore-forming structures that may resemble small horns. It is a rare
or very uncommon group, distributed worldwide, that tends to grow in soils with
constant moisture or very humid periods.
The plant thallus consists of green lobes, ranging from a few millimeters to a
few centimeters, attached to the substrate, translucent or not, appearing
fragile and unable to stay moist without liquid water around them. The lobes may
exhibit small structures such as propagules, central nerves, hairs, folds, or
frequently nodules where symbiotic cyanobacteria live, which provide organic
nitrogen to the plant. Their thallus lobes lack truly specialized cells, such as
conducting vessels. The lower surface usually has elongated hair-like cells (rhizoids)
that anchor the plant to the substrate. The cells of these thalli have only one
copy of each chromosome, constituting the gametophyte phase in the life cycle of
this group. On the upper surface of the lobes, but immersed in the thallus, the
structures forming sperm and ovules appear. The sperm cells are released into
the environment by breaking the epidermal layer and they swim in presence of
water, aided by rain splashes, to the female organs containing an ovule.
Fertilization of the ovule produces a cell with two copies of each chromosome (diploid
cells) that will form the sporophyte phase. The sporophyte grows on the mother
plant and is basically composed of a short stalk carrying a long cylindrical
sporangium, with an epidermis containing stomata. The sporangium has a central
support column and two lateral valves, which open upon drying to release the
spores, although the sporangium continues to grow from bottom to top during
spore release.
The phylum Anthocerotophyta is a primitive group of terrestrial plants that
likely appeared during the Devonian period. It is a group halfway between mosses
(Phylum Bryophyta) and truly vascular plants (Phylum
Lycopodiophyta and other more derived ones).
Phylum: Anthocerotophyta