First Vascular Plants Flashcards
What features are shared among members of Rhyniopsida?
No leaves No roots Naked axes (green and photosynthetic) Dichotomous branching Terminal sporangia Simple, slender protosteles, centrarch maturation Small plants
What is the oldest class of vascular plants and when did they evolve?
Rhyniopsida. They evolved in the Upper Silurian and Lower Devonian. Genera include Cooksonia and Rhynia.
What class of species has cauline sporangia (growing on their stems) and when did they evolve?
Zosterophyllopsida. They evolved in the Upper Silurian to Lower Devonian.
What are some key distinctions between Rhyniopsida and Zosterophyllopsida?
Zosterophyllopsida have some stems bearing enations (small spines or flaps of tissue), cauline sporangia, more robust protosteles, and are larger in size.
What class of plants has terminal sporangium in pairs and when did they evolve?
Trimerophytopsida. They evolved in the Middle and Upper Devonian.
What are the key characteristics that distinguish members of the Trimerophytopsida?
More variable branching (dichotomous, trichotomous) and growth habit (monopod oak and pseudomonopodial branching).
What is pseudomonopodial branching?
Branching that appears to be monopodial, but is actually a modification of dichotomous branching.
What class of plants have their sporangium in synangia (two or more fused sporangium) in the axils of forked enations?
Psilophytopsida.
What division are Rhyniopsida, Zosterophyllopsida, Trimerophytopsida, and Psilotophytopsida part of?
Tracheophyta.
What is the only non-vascular genus of plants in the Rhyniopsida and is suspect of its placement due to the fact that it does not have secondary wall thickenings?
Aglaophyton (A. major).
Which class of plants in the Tracheophyta has actinosteles and haplosteles?
Psilotophytopsida.
What is a polysporangiophyte?
Plants with more than one sporangium present per sporophyte.
What are three types of lignification in tracheids (i.e cell wall thickenings).
Annular (rings), helical (spiral), and sclariform.
Why are enations not called leaves?
They lack vascular tissue.
What are the appropriate -endings for divisions, subdivisions, classes, orders, and families respectively?
Division: -phyta Subdivision: -phytina Class: -opsida Order: -ales Family: -aceae
What are three types of protosteles?
Haplosteles, actinosteles, and plectosteles.
What are two types of siphonosteles?
Simple siphonosteles-selenosteles and dictyosteles.
What are two types of eusteles?
Simple eustels and atactosteles.
