25 Seedless Plants

Adventitious

Describes an organ that grows in an unusual place, such as roots growing from the side of a stem.

Antheridium

Male gametangium.

Archegonium

Female gametangium.

Capsule

Case of the sporangium in mosses.

Charophyte

Other term for green algae; considered the closest relative of land plants.

Club mosses

Earliest group of seedless vascular plants.

Diplontic

Diploid stage is the dominant stage.

Embryophyte

Other name for land plant; embryo is protected and nourished by the sporophyte.

Extant

Still-living species.

Extinct

No-longer-existing species.

Fern

Seedless vascular plant that produces large fronds; the most advanced group of seedless vascular plants.

Gametangium

Structure on the gametophyte in which gametes are produced.

Gemma

(Plural, gemmae) Leaf fragment that spreads for asexual reproduction.

Haplodiplodontic

Haploid and diploid stages alternate.

Haplontic

Haploid stage is the dominant stage.

Heterosporous

Produces two types of spores.

Homosporous

Produces one type of spore.

Hornworts

Group of non-vascular plants in which stomata appear.

Horsetail

Seedless vascular plant characterized by joints.

Lignin

Complex polymer impermeable to water.

Liverworts

Most primitive group of the non-vascular plants.

Lycophyte

Club moss.

Megaphyll

Larger leaves with a pattern of branching veins.

Megaspore

Female spore.

Microphyll

Small size and simple vascular system with a single unbranched vein.

Microspore

Male spore.

Mosses

Group of bryophytes in which a primitive conductive system appears.

Non-vascular plant

Plant that lacks vascular tissue, which is formed of specialized cells for the transport of water and nutrients.

Peat moss

Sphagnum.

Peristome

Tissue that surrounds the opening of the capsule and allows periodic release of spores.

Phloem

Tissue responsible for transport of sugars, proteins, and other solutes.

Protonema

Tangle of single-celled filaments that forms from the haploid spore.

Rhizoids

Thin filaments that anchor the plant to the substrate.

Seedless vascular plant

Plant that does not produce seeds.

Seta

Stalk that supports the capsule in mosses.

Sporocyte

Diploid cell that produces spores by meiosis.

Sporophyll

Leaf modified structurally to bear sporangia.

Sporopollenin

Tough polymer surrounding the spore.

Streptophytes

Group that includes green algae and land plants.

Strobili

Cone-like structures that contain the sporangia.

Tracheophyte

Vascular plant.

Vascular plant

Plant containing a network of cells that conducts water and solutes through the organism.

Vein

Bundle of vascular tissue made of xylem and phloem.

Whisk fern

Seedless vascular plant that lost roots and leaves by reduction.

Xylem

Tissue responsible for long-distance transport of water and nutrients.