What types of plants are Heterosporous?

Conifers are heterosporous and, in addition, produce highly specialized, complex reproductive and dispersal structures called seeds. Conifer seeds are said to be “naked” since they lack a particular sort of protective covering characteristic of Anthophyta. Coniferophyta are therefore said to be “gymnospermous.”

What two phyla contain seeds?

Five phyla of seed plants still exist today.

• Cycadophyta – the cycads, or sago “palms”
• Ginkgophyta – the ginkgos.
• Coniferophyta – the conifers.
• Gnetophyta – the gnetophytes (yes, that’s the best I can do)
• Anthophyta – the flowering plants.

Cycads | Back to Top Cycads, like all seed plants, are also heterosporous, unlike the ferns which are all homosporous. Cycad cones are unisexual, in fact the plants producing them are dioecious, having separate male and female plants.

A heterosporous life history occurs in some pteridophytes and in all seed plants. It is characterized by morphologically dissimilar spores produced from two types of sporangia: microspores, or male spores, and megaspores (macrospores), or female spores.

Whereas lower vascular plants, such as club mosses and ferns, are mostly homosporous (producing only one type of spore), all seed plants, or spermatophytes, are heterosporous, producing two types of spores: megaspores (female) and microspores (male).

Release of spores in a suitable environment will lead to germination and a new generation of gametophytes. … Whereas lower vascular plants, such as club mosses and ferns, are mostly homosporous (produce only one type of spore), all seed plants, or spermatophytes, are heterosporous.

The evolution of seeds allowed plants to decrease their dependency upon water for reproduction. Seeds contain an embryo that can remain dormant until conditions are favorable when it grows into a diploid sporophyte.

By the Late Devonian, forests of large, primitive plants existed: lycophytes, sphenophytes, ferns, and progymnosperms had evolved. Most of these plants have true roots and leaves, and many were quite tall. The tree-like Archaeopteris, ancestral to the gymnosperms, and the giant cladoxylopsid trees had true wood.

Prehistoric Plants

Montsechia vidalii