5. Seedless Plants

Adventitious: describes an organ that grows in an unusual place, such as a roots growing from the side of a stem

Antheridium: male gametangium

Archegonium: female gametangium

Capsule: the case of the sporangium in mosses

Charophyte: another term for green algae; considered the closest relative of land plants club mosses the earliest group of seedless vascular plants

Diplontic: the diploid stage is the dominant stage of embryophyte another name for a land plant; the 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: the most primitive group of the non-vascular plants

Lycophytes: Are a group of vascular plants that include the 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: a 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 the transport of sugars, proteins, and other solutes

Protonema: a tangle of single-celled filaments that form from the haploid spore

Rhizoids: thin filaments that anchor the plant to the substrate

Seedless vascular plant: a plant that does not produce seeds

Seta stalk: that supports the capsule in mosses

Sporocyte: a 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: a seedless vascular plant that lost roots and leaves by reduction

Xylem tissue: responsible for long-distance transport of water and nutrients