9 Lycopodium obscurum a forest-dwelling lycophyte The sporophylls are organized into a terminal strobilus.
10 Lycopodium obscurum sporophytes demonstrate dichotomous branching. Microphylls are spirally arranged with some flattening of the branch system.Lycopodium obscurum strobili are not interrupted by microphylls.Sporophylls are not photo-synthetic.
11 Strobilus Longisection sporophyllsterile jacketspores (1N)sporangiumstalkAll the spores are the same small size, so Lycopodium is homosporous.The spores are shed into the wind.
17 Rhynia was a Psilotum-like swamp dwelling organism living with Protolepidodendron, the herbaceous ancestor of woody Lepidodendron in swamps during the Devonian period.
18 Lepidodendron was a large lycophyte tree living in marshes Lepidodendron was a large lycophyte tree living in marshes. Dead plants and spores built up in the peat of the marshes, were later overrun with sediments, and by heat and pressure were converted to coal.