Ophioglossaceae sentence example
- The morphology of the fertile spike is a disputed question, upon the answer to which the systematic position of the Ophioglossaceae largely rests.
- The important bearing of this question on the relationship of the Ophioglossaceae to the phyla of the Filicales and Lycopodiales will be obvious.
- In these respects, in the megaphyllous habit and in certain anatomical features, the Ophioglossaceae approach the Filicales.
- The position of the Ophioglossaceae can at present only be regarded as an open question, in considering which the possible antiquity of the group must be borne in mind.Advertisement
- Little or nothing is known of Palaeozoic Ophioglossaceae.
- The family as a whole is of great interest, as presenting points of contact with various recent orders, especially Hymenophyllaceae, Osmundaceae and Ophioglossaceae; the group appears to have been a synthetic one, belonging to a primitive stock (the Primofilices of Arber) from which the later Fern families may have sprung.
- Of the Ophioglossaceae there are no satisfactory examples; one of the few fossils compared with a recent species, Ophioglossum palmatum, was described several years ago from Triassic rocks under the name Cheiropteris, but the resemblance is one of external form only, and practically valueless as a taxonomic criterion.
- Usually it grows exposed to the light and contains chlorophyll, but subterranean saprophytic prothalli also occur in the Lycopodiaceae and Ophioglossaceae (fig.
- The Ophioglossaceae are homosporous, and the prothalli, which are known in species of all three genera, are subterranean and saprophytic (fig.Advertisement