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Equisetum arvense, the field horsetail or common horsetail, is an herbaceous perennial plant in the Equisetidae (horsetails) sub-class, native throughout the arctic and temperate regions of the Northern Hemisphere. It has separate sterile non-reproductive and fertile spore-bearing stems growing from a perennial underground rhizomatous stem system.
Equisetum (/ ˌ ɛ k w ɪ ˈ s iː t əm /; horsetail) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. [2]Equisetum is a "living fossil", the only living genus of the entire subclass Equisetidae, which for over 100 million years was much more diverse and dominated the understorey of late Paleozoic forests.
In the only extant genus Equisetum, these are small leaves (microphylls) with a singular vascular trace, fused into a sheath at each stem node. However, the leaves of Equisetum probably arose by the reduction of megaphylls , as evidenced by early fossil forms such as Sphenophyllum , in which the leaves are broad with branching veins.
Equisetum pratense, commonly known as meadow horsetail, shade horsetail or shady horsetail, is a widespread horsetail (Equisetophyta) and it is a pteridophyte.Shade horsetail can be commonly found in forests with tall trees or very thick foliage that can provide shade and tends to grow closer and thicker around streams, ponds and rivers.
Equisetum palustre, the marsh horsetail, [2] is a perennial herbaceous pteridophyte belonging to the subclass of horsetails (Equisetidae). It is widespread in cooler regions of Eurasia and North America .
Microphylls contain a single vascular trace. The clubmosses and horsetails have microphylls, as in all extant species there is only a single vascular trace in each leaf. [ 2 ] These leaves are narrow because the width of the blade is limited by the distance water can efficiently diffuse cell-to-cell from the central vascular strand to the ...
If children swallow them, they become dangerous because they grow bigger and get lodged in the body. “The biggest hazard with them is that when they’re ingested, they expand,” Miller says.
Environmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus.This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications.