Class:
Ophioglossopsida
Order:
Ophioglossales
These
ferns are eusporangiate and homosporous.
The sporangia are thick walled and borne on a fertile spike which
projects from the upper surface of the leaf.
The sporophyte stem is short and fleshy. When a new fern leaf "unfolds", (vernation) it is
said to be "non-circinate", that is it does not "uncoil" (circinate
vernation).
Genus:
Ophioglossum
These
ferns are known as the "adder's tongue" ferns.
They have one or two lanceolate leaves (shaped like the head of a
spear), with an erect unbranched modified fertile segment bearing two rows of
sporangia near the summit. This
genus is very rare in Manitoba.
Examine the preserved material and the herbarium specimens and note the structures mentioned above.
Examine the slide (#65) of a L.S. of the fertile spike and note the homosporous condition.
Genus:
Botrychium
These
ferns are called the "grape ferns", because of the large, clustered
sporangia on the fertile portion of the frond. This frond has a single common
stalk from which clusters of sporangia arise at the apex, and sterile,
pinnately divided leaf segments arise below.
Several species occur in Manitoba.
Examine the preserved and herbarium specimens and note the distinguishing characteristics.
Examine the X.S. slide (#66) of the Botrychium sp. This is a composite slide showing three sections. The small specimen is a root, the medium sized specimen is a rhizome and the large cross section specimen is a rachis (the axis of a compound leaf on which the leaflets are borne, pronounced - "ray kiss"). Note that the stele of the rhizome is an ectophloic siphonostele, with one leaf trace. Also note that the root is a protostele. Do not attempt to differentiate between the various cell and tissue types.
