heterosporous -- Producing two different sizes or kinds of spores. These may come from the same or different sporangia, and may produce similar or different gametophytes. Contrast with homosporous, and compare with heterosporangiate.
heterosporous Producing two distinct types of spores.
heterotherm An animal whose body temperature fluctuates markedly; "cold-blooded." ...
Selaginella is a heterosporous member of the lycophytes. Some species of this genus are able to withstand drying out by going dormant until they are rehydrated. For this reason these forms of the genus are commonly called resurrection plants.
Lepidodendron was a heterosporous tree common in coal swamps. As with many large plant fossils, one rarely if ever finds the entire tree preserved intact.
Vascular plant spores are always haploid and vascular plants are either homosporous or heterosporous. Plants that are homosporous produce spores of the same size and type.
Gymnosperms
Fossil from the Devonian period reveal fernlike plants that were heterosporous; that is, produced two kinds of spores.
microspores (male) and
megaspores (female).
(Science: plant biology) A haploid spore produced by a plant sporophyte that develops into a male gametophyte. In seed plants, it corresponds to the developing pollen grain at the uninucleate stage. The smaller of the spores of a heterosporous ...
 See also: Plant, Life, Gametophyte, Sporophyte, Spore
  
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