Study Set Content:
whisk ferns scientific name
Psilotum
Loosely resemble small, green whisk brooms. Exactly where these plants fit in the Plant Kingdom is not clear.
Division Psilophyta (The Whisk Ferns
They have been associated with a number of extinct plants called (blank) that flourished perhaps 400 million years ago
psilophytes
consist almost entirely of dichotomously forking (evenly forking) aerial stems and are unique among living vascular plants in having neither leaves nor roots.
o Psilotum sporophytes
are tiny, green, superficially leaflike, veinless, photosynthetic flaps of tissue, are spirally arranged along the stems
Enations
Division Psilophyta Photosynthesis takes place in the outer cells of the stem
epidermis and cortex
Sporangia that are fused together in threes and resemble miniature yellow pumpkins are produced at the tips of very short, stubby branches in the upper parts of the angular stems
Immature sporangium
lack pigmentation, no chlorophyll and absorb their nutrients via onecelled, rootlike rhizoids aided by mycorrhizal fungi.
Gametophytes of whisk ferns
he oldest plant known to have had xylem
Cooksonia
One group of these fossil plants, of which (blank) are examples had naked stems (no photosynthetic flaps) and terminal sporangia
Cooksonia and Rhynia
second group of fossils ad somewhat rounded sporangia produced along the upper parts of naked stems
Zosterophyllum
Whisk ferns are of little economic importance?
True
Their spores have a slightly oily feel and were once used by Hawaiian men to reduce loincloth skin irritations. Hawaiians also made a laxative liquid by boiling this plants in water
Whisk ferns
number of known species of club mosses
950
mostly look enough like large true mosses that the Swedish naturalist (blank) lumped both together in a single class.
Linnaeus
number of genera of club mosses
two major genera and two minor genera of club mosses.
two major genera of lycophyta
Lycopodium, with about 50 species, and Selaginella, with over 700 species
Ground Pines
Lycopodium
often grow on forest floors. They are sometimes called ground pines, partly because they resemble little Christmas trees, complete with “cones” that are upright or, in a few species, hang down
Lycopodium
height of ground pines
less than 30 centimeters (1 foot) tall, although some tropical species grow to heights of 1.5 meters (5 feet) or more
