Glossary

acroscopicon the side towards the apex of the frond
adnatein ferns, usually refers to the base of a pinnule being joined along its length to the midrib, rather than being stalked. May be 'half-adnate' or any other fraction.
annulusa row of cells with thickened walls on the sporangium, which contracts to tear the sporangium open, then springs back to throw the spores out.
auriclea small, usually rounded, lobe - literally 'a small ear'
basiscopicon the side towards the base of the frond
bi-pinnatetwice divided (see pinnate)
costathe midrib of a pinna
crozierthe coiled young fern frond (see Parts of a Fern)
dimorphichaving two different forms - in ferns this means that the vegetative fronds differ from the fertile, spore-bearing fronds
eglandularwithout glands
entirenot toothed or lobed
frondthe leaf of a fern that arises from the rhizome
gametea male or female sex cell, usually with one set of chromosomes
gametophytea tiny plant that germinates from the spore and carries the gametes
glandan organ that produces secretions. In ferns, these often look like minute drumsticks. When the glands on the surface of a frond are very dense, they can give the frond a greyish, or mealy appearance. See pictures below.
glandularhaving glands
indusiuma membrane that covers the sporangia
inflexedabruptly bent inwards
laminathe leafy part of a fern frond, above the stipe, or stalk
lanceolateshaped like a lance or spear head, tapering to both ends but wider nearer the base
lobea section of an organ, usually rounded
ovateegg-shaped, with the broadest part nearer to the base
oblanceolateshaped like a lance, but with the broadest part nearer to the apex
obovateegg-shaped, but with the broadest part nearer to the apex
pinnathe first division of a fern frond
pinnateonce divided, for example in ferns, Polypodium or Blechnum. Twice divided fronds are bi-pinnate, e.g. common male fern, and three-times divided are tri-pinnate, e.g. broad buckler fern.
pinnulethe first division of a pinna
pinnuletthe first division of a pinnule
prothallus(plural prothalli) and the gametophyte plant. See Life Cycle diagram
rachisthe midrib of the lamina in ferns, the axis of a compound leaf or inflorescence in angiosperms
rhizomea modified stem, which may be root-like, from which the fronds and true roots emerge. Rhizomes may be creeping, above or below ground, or they may be upright.
scalea membranous, leaf-like structure, can be present on the rhizome, stipe, rachis, costa, and sometimes on the under-surface of the lamina
sorus(plural sori) a collection of sporangia. Usually on the under-surface of the frond, but may be on the ends of fronds, as in the royal fern Osmunda regalis. Sori may be naked, or covered by an indusium.
sporangiumthe organ where spores are produced
sporethe reproductive unit in ferns
sporophytethe alternate generation to the gametophyte , the conspicuous fern that bears spores
stipethe stalk of the frond, from the rhizome to the start of the lamina
tootha small pointed projection on the edge of the leaf
tri-pinnatethree-times divided
truncateappearing cut-off, usually at the base of the lamina. The opposite of tapering, when the size of the pinnae reduces progressively towards the base.
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