Search results
Results from the WOW.Com Content Network
In botany, an operculum (pl.: opercula) or calyptra (from Ancient Greek καλύπτρα (kalúptra) 'veil') is a cap-like structure in some flowering plants, mosses, and fungi. It is a covering, hood or lid, describing a feature in plant morphology .
Moss leaf under microscope, showing gemmae and a hair point (40x) Moss gametophytes have stems which may be simple or branched and upright (acrocarp) or prostrate (pleurocarp). The early divergent classes Takakiopsida, Sphagnopsida, Andreaeopsida and Andreaeobryopsida either lack stomata or have pseudostomata that do not form pores.
The operculum is long-rostrate, which means it has an apical beak narrowing to a slender tip. [2] [3] [4] Cyathophorum bulbosum is dioicous, meaning that male and females are separate ‘plants’.The life cycle is dominated by the gametophyte stage. There are no other moss species within Australia that look similar.
Botanical illustration of Bartramiopsis lescurii. 1 = Plant dry, 2 = Moist plant, with capsule, 3 = Moist plant, without capsule, 4 = Capsule with calyptra, 5 = Mature capsule without operculum, 6 = Leaf showing hairs at margin and lamellae on upper side, 7 = Leaf showing narrower blade and more curved tip, 8 = Leaf tip, upper side, showing lamellae, 9 = Underside of leaf tip,10 = Cross ...
This articulation of the teeth is termed arthrodontous and is found in the moss subclass Bryopsida. In other groups of mosses, the capsule is either nematodontous with an attached operculum (as in the Polytrichopsida), or else splits open without operculum or teeth. There are two subtypes of arthrodontous peristome. [1]
A leaf of P. urnigerium measures 2.5-6mm [7] in length and consists of a unistratose lamina with many lamellae on the upper surface (adaxial side) of the leaf (30-46 lamellae [7] stacked with pillars of 4-7 cells [7] each). Lamellae are vertical stacks of cells that provide many beneficial functions. [9]
The cells of the leaf blade are prosenchymatic, many times longer than wide, with pointed ends interlocking. The sporophyte consists of a regularly shaped sporangium on a long stalk or seta. The spores are distributed via a ring-shaped opening with two rows of teeth, the peristome, which before ripeness is closed by a beak-shaped operculum.
The cells that the base of the leaf are usually longer. [4] [2] The costa is narrow and wide in the middle of the leaf with the abaxial surface bearing short spines. [4] There is normally one setae per perichaetium, the capsules are exserted and strongly curved. The operculum is curved and the calyptra is cucullate and smooth.