Moss Life Cycle Diagram Unlabeled – Blank Sheet With Key

All 14 stages and parts on the diagram

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Spore to plant 5

Spores Tiny grains that drift on the air. Each can start a new moss.
Protonema The green branching thread a spore grows into.
Bud It forms on the protonema and grows into a leafy plant.
Gametophyte (leafy plant) The leafy green moss plant. It makes the sperm and the eggs.
Rhizoids Fine threads that anchor the plant. They are not true roots.

Sperm and egg 4

Antheridium The male organ. It makes the sperm.
Sperm Tiny swimmers from the antheridium. They need water to reach the egg.
Archegonium The female organ: a flask with a long neck and one egg.
Egg It sits in the base of the archegonium. A sperm fertilizes it.

The sporophyte 5

Young sporophyte It grows from the fertilized egg, on top of the leafy plant.
Seta (stalk) The long stalk of the sporophyte. It lifts the capsule into the air.
Calyptra (cap) A loose cap over the capsule, left over from the archegonium.
Capsule (sporangium) The urn at the top of the seta. The spores form inside it.
Operculum (lid) The lid of the capsule. When it comes off, the spores can leave.

How this list was compiled: Every name was checked on 2026-09-30 against sources read that day; a name is kept only when two of them use it. (1) John N. Martin, Botany for Agricultural Students, 1919, public domain, https://archive.org/details/botanyforagricul00mart (true mosses: the leafy green plant is the gametophyte, with rhizoids; club-shaped antheridia and flask-shaped archegonia with long necks stand on the stem tip, in many mosses on the same plant, in others on separate plants; the sperms swim down the neck when there is moisture and fertilize the egg; the fertilized egg grows in place into the sporophyte, with a foot, a stalk called the seta and a sporangium, or capsule, in which the spores are produced; the enlarged archegonium is carried up as a pointed cap; the lid, or operculum; a spore first produces a branching filament, the protonema, and the leafy plants grow from buds on it; one protonema may produce many buds). (2) Wikipedia, text only: Moss, https://en.wikipedia.org/wiki/Moss (the life cycle starts with a spore that germinates to produce a protonema; from it grows the gametophore, with stems and leaves; rhizoids anchor the plant; antheridia and archegonia; in the presence of water sperm swim to the archegonia; the sporophyte is a long stalk, the seta, and a capsule capped by the operculum, sheathed by the calyptra, the remains of the archegonium, which usually drops off once the capsule is mature; a mat of protonemata may grow several shoots, a clump of moss), Protonema, https://en.wikipedia.org/wiki/Protonema (the bud), Sporophyte, https://en.wikipedia.org/wiki/Sporophyte (the sporophyte develops from the zygote, the fertilized egg cell, within the archegonium; young sporophytes of a moss), and Archegonium, https://en.wikipedia.org/wiki/Archegonium . (3) C. Stuart Gager, Fundamentals of Botany, 1916, public domain, https://archive.org/details/fundamentalsofbo00gagerich (chapter XV, Life history of a moss: antheridia with sperms that bear two cilia; archegonia with a neck and a venter containing the egg; the capsule with its spores; the top of the archegonium carried up as a cap, the calyptra; the operculum). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain curves; own work, nothing traced. Licence: own work

How it works

This moss life cycle diagram is unlabeled: three drawings with arrows between the stages and fourteen parts to name. Spores grow into leafy shoots, two shoot tips are cut open and enlarged, and one shoot carries its stalk and capsule.

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Unlabeled diagram of life cycle of moss: the word list

First drawing: spores, protonema, bud, gametophyte (the leafy plant) and rhizoids. Second: antheridium, sperm, archegonium and egg. Third: young sporophyte, seta, calyptra, capsule and operculum. The names run in the order of the cycle.

Lines that end close together

Two lines reach the thread on the ground: one stops on the thread itself, the protonema, and one on the small tuft standing on it, the bud. In the middle drawing one line stops on the wall of a flask, the archegonium, and one on the round body inside the other flask, the egg. At the bottom, the hood still covering a capsule is the calyptra, the bare capsule stands on the next plant, and the loose piece beside it is the operculum.

The grains falling from the open capsule are spores too. Only the ones at the top left have a line.
The two cups of leaves in the middle drawing are the tips of a male shoot and a female shoot.

Questions and answers

Is moss a vascular plant?

No. Mosses are non-vascular plants. They have no flowers and no seeds, and they reproduce with spores, which is why the diagram begins and ends with spores.

What are the three parts of a moss sporophyte?

Foot, seta and capsule. The foot is the lower end, pushed into the stem of the leafy plant to take up food, so it is hidden and has no line here. The seta is the stalk, and the capsule holds the spores.

What is the peristome of a moss capsule?

A ring of teeth around the mouth of the capsule, just under the lid, which helps scatter the spores. Some mosses have none. It is too small to draw at this size, so the sheet does not ask for it.

Do moss sperm have flagella?

Yes, two. Moss sperm are biflagellate: each swims with a pair of flagella. On the sheet they are the small curled swimmers between the two shoot tips.