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Like other ferns, members of the Marsileaceae produce spores, but not seeds when they reproduce. Unlike other ferns, the spores in this family are produced inside sporocarps . These are hairy, short-stalked, bean -shaped structures usually 3 to 8 mm in diameter [ 1 ] with a hardened outer covering.
A fern spike is characterized by a suddenly higher abundance of fern spores following a disaster, generally accompanied by a decrease in other plant species as indicated by their pollen. Eventually fern abundance will decrease, hence the term "spike" describing the pattern.
Fern spores are borne in sporangia which are usually clustered to form sori. The sporangia may be covered with a protective coating called an indusium. The arrangement of the sporangia is important in classification. [6] In monomorphic ferns, the fertile and sterile leaves look morphologically the same, and both are able to photosynthesize.
The spores of lycopods are highly flammable and so have been used in fireworks. [30] Lycopodium powder, the dried spores of the common clubmoss, was used in Victorian theater to produce flame-effects. A blown cloud of spores burned rapidly and brightly, but with little heat. (It was considered safe by the standards of the time.) [citation needed]
Onoclea sensibilis, the sensitive fern, also known as the bead fern, is a coarse-textured, medium to large-sized deciduous perennial fern. The name comes from its sensitivity to frost, the fronds dying quickly when first touched by it. It is sometimes treated as the only species in Onoclea, [2] but some authors do not consider the genus ...
The fertile leaves appear first; their green color slowly becomes brown as the season progresses and the spores are dropped. The spore-bearing stems persist after the sterile fronds are killed by frost, until the next season. The spores must develop within a few weeks or fail. The Osmundastrum cinnamomeum fern forms huge clonal colonies in ...
[4] [5] "Frond" is commonly used to identify a large, compound leaf, but if the term is used botanically to refer to the leaves of ferns and algae it may be applied to smaller and undivided leaves. Fronds have particular terms describing their components. Like all leaves, fronds usually have a stalk connecting them to the main stem.
The leaves contain a single, unbranched vascular strand, and are microphylls by definition. [6] They are usually arranged in spirals. [ 7 ] The kidney-shaped (reniform) spore -cases ( sporangia ) contain spores of one kind only, ( isosporous, homosporous ), and are borne on the upper surface of the leaf blade of specialized leaves (sporophylls ...