peristome

[ per-uh-stohm ]

noun

1. Botany. the one or two circles of small, pointed, toothlike appendages around the orifice of a capsule or urn of mosses, appearing when the lid is removed.
2. Zoology. any of various structures or sets of parts that surround or form the walls of a mouth or mouthlike opening.

peristome

/ ˈpɛrɪˌstəʊm /

noun

1. a fringe of pointed teeth surrounding the opening of a moss capsule
2. any of various parts surrounding the mouth of invertebrates, such as echinoderms and earthworms, and of protozoans

peristome

/ pĕr′ĭ-stōm′ /

1. A fringe of toothlike appendages surrounding the mouth of the spore capsule of some mosses. The teeth unfold under damp conditions and curl up under dry conditions to disperse spores gradually.
2. The area or parts around the mouth in certain invertebrates, such as the echinoderms.

Derived Forms

• ˌperiˈstomal, adjective

Other Words From

• peri·stomal per·i·sto·mat·ic [per-, uh, -st, uh, -, mat, -ik], peri·stomi·al adjective

Word History and Origins

Origin of peristome¹

From the New Latin word peristoma, dating back to 1790–1800. See peri-, -stome

Word History and Origins

Origin of peristome¹

C18: from New Latin peristoma, from peri- + Greek stoma mouth

Example Sentences

The "rim" of the cup or peristome is often colourful, it is thought, to catch the eye of passing bugs.

From BBC

During each forward movement the column is arched downwards so that the peristome is in contact with the surface along which the animal is moving.

From Project Gutenberg

Grooves and peristome protected by small plates, which can open over the grooves.

From Project Gutenberg

The tentacles surround an area known as the peristome, in the middle of which there is an elongated mouth-opening surrounded by tumid lips.

From Project Gutenberg

When moist the peristome closes hygrometrically over the orifice more or less; when drier the teeth or processes commonly bend outward or recurve; and then the spores more readily escape.

From Project Gutenberg