Botany · Ch 2 — Plant Kingdom
Funaria
Funaria
Funaria (Class Bryopsida, Order Funariales), commonly called 'cord moss', is a worldwide moss; Funaria hygrometrica, the common species, grows in tufts on rocks, tree trunks and damp walls/soil, and contributes to soil formation (pedogenesis).
The gametophyte plant body is small (1–3 cm), an erect, radially symmetrical stem covered in small, simple, spirally arranged leaf-like structures (broad-based, sessile, pointed-tipped), anchored by multicellular rhizoids with oblique cross-walls. In transverse section the axis shows an outer chloroplast-bearing epidermis, a parenchymatous cortex (its outer cells turning reddish-brown and thick-walled with age, with small leaf traces visible), and a central cylinder of long, narrow, colourless, protoplast-free cells that conduct water and minerals. The leaf itself has a well-defined, several-layered midrib for conduction and a single-cell-thick lamina rich in chloroplasts.
Funaria reproduces vegetatively by fragmentation of the primary protonema, by secondary protonema arising from any part of the gametophyte, by gemmae on the protonema's terminal cells, and by bulbils on the rhizoids. Sexual reproduction is monoecious: the antheridial branch (protected by perigonial leaves, with sterile hair-like paraphyses among the antheridia that hold water by capillary action and secrete mucilage) and the archegonial branch (protected by perichaetial leaves, arising laterally at the base of the male branch) sit on the same plant. Each flask-shaped archegonium has a broad venter (containing the egg and a venter canal cell) and a long neck (with neck canal cells). Rain splash carries antherozoids from the antheridial head to the archegonial head, where chemotaxis guides them to the archegonium; only one fertilizes the egg, forming the diploid zygote that starts the sporophyte generation. …
What this figure shows. An erect, slender leafy gametophyte with small spirally arranged leaves along the stem, multicellular rhizoids anchoring it at the base, and a stalked, slightly curved capsule rising above t …
What this figure shows. A cross-section of the stem showing three zones: an outer chlorophyll-bearing epidermis, a parenchymatous cortex (reddish-brown and thick-walled in older stems), and a central strand of long, narrow, colourless, protoplast-free cells that conduct w …
What this figure shows. A germinating spore producing a branched, thread-like green protonema, from which secondary protonema and gemmae arise; buds developing on the protonema each grow into a new leafy gametophyte. …
What this figure shows. (a) An antheridial head: a cluster of club-shaped antheridia surrounded by protective perigonial leaves and interspersed with long sterile hairs called paraphyses. (b) An archegonial head: flask-shaped archegonia (each with a swollen venter and long neck) surrounded by perichaetial leav …
What this figure shows. A longitudinal section of the mature sporophyte capsule showing, from base to tip: the seta, the sterile photosynthetic apophysis (with stomata), the fertile theca with a central columella surrounded by the spore sac (itself surrounded by an air-filled sac crossed by trabeculae), and the apical operculum with a toothed, hygroscopic peristome and annulus at …
What this figure shows. A haplo-diplontic life-cycle chart: a haploid primary protonema gives rise to buds that grow into the leafy Funaria gametophyte, which is monoecious — the same plant bears a male branch (with a perigonium and antheridium producing antherozoids) and a female branch (with a perichaetium and archegonium producing an oosphere). Fertilisation gives a diploid zygote that develops into a sporophyte generation (sporogonium) whose spore mother cells undergo meiosis inside the spore cavity to produce haploid meiospores; these germinate to restart the gametophyte generation. A parallel vegetative-reproduction loop shows bul …