Devonian period
400 mya
they dominated by carboniferious period
360 mya
-mild warm climate, swampy lowlands, woody tree like lycopods, horsetails and ferns
100
ORDER PSILOTALES
what are the common characteristics?
GENUS NAME: Psilotum
sporophytes have photosynthetic stems and underground rhizomes
-produces spores->gametophytes
gametophyte tiny and non photosynthetic
-fungi provide it with nutrients
-remains below the soil surface
100
what is a sorus?
cluster of sporangia
200
What are some characteristics of the division lycophyta?
NOTE GENUS NAME: LYCOPODIUM
larger than bryophyta
sporophyte grows vertically
dichotomous branching
spore producing cones=strobili
-defined as a central axis surrounded by tightly packed small scale like structures
microphylls
- needle like photosynthetic
- surround stems
200
ORDER EQUISETALES
what are the common characteristics of the equisetales?
horsetails
sporophyte dominant
gametophyte tiny and remains at soil
WHORLED stem arrangement
-multiple stems or leaves emerge from single node on the stem
-whorled STROBILI TOO
reduced scale like leaves
photosynthetic stems
may have silica in cell walls
strobilus
homosporous
GENUS EQUISETUM
200
when are spores released?
when the annulus dries and causes sporangium to split open
300
In a cone (strobilis) where is the sporophyll and sporangium?
The sporophyll is each little scaly leaf that contains the swollen sporangium
300
What is unique about whorled strobili in the equisetales?
sporangiophores are attaced to central axis in whorls
lower surface of each sporangiophore are multiple sporangia
300
what is annulus?
rim of tissue that expands explosively to release spores
first appear in fossil record in carboniferous period (32omya)
diverse in size and morphology
water essential for sexual reproduction
dominany sporophyte
-fronds and rhizomes
no true roots
some ferns in temperate zones: fleshy horizontally growing rhizomes
spores develop into multicellular HEART SHAPED gametophyte
-remains at soil surface
500
Is monilophyta a monophyletic group?
YES
includes all the seedless descendents of a common ancestor with megaphylls
500
Features of the fillicates?
homosporous
gametophyte BISEXUAL (prod egg and sperm at soil surface)
sporophyte dominant
sporophyte: large megaphylls
-fronds, network of veins)
sporangia often appear in clusters on the underside of fronds
annulus!
-rim of tissue on sporangium
-facilitates spore dispersal