Horsetail gains it's name from it's bristly appearance. The genus name Equisetum is derived from the Latin words equus, meaning horse, and seta, meaning bristle.
The plant grows in two stages. The first stage occurs during the spring, when the it sprouts a fertile hollow stem that is similar to asparagus. After the fertile stems have withered and died, during the summer months, thin, green, barren stems branch out (which is the stage where it looks like a horse's tail). It is during this stage that the plant is harvested for use.
It is perhaps this herbs growing cycle that has led to it's use as a fertility herb in magick. It is generally after unsuccessful attempts at conception that we turn to magick as an aid in conception, and it is at this time that we believe our previous fertility is in a barren state. The same can be said for any period of creativity, where we feel our well has run dry. Symbolically, Horsetail is a herb for new beginnings, and ruled by the element of Earth, this herb is an excellent addition to fertility charms.
Spiritually Horsetail is an aid in dealing with loss and depression. Associated with the Five of Cups in the Tarot, which is the card of "crying over split milk". In this card the person is unable to look past what they have lost, what they have not got, to see the joy in what they do have. The figure in the Five of Cups is so full of sorrow over his two spilt cups, that he finds no joy in what the remaining cups have to offer.
This too ties in with it's use as a fertility herb. When using magick as an aid to fertility and creativity, it is important to focus on the positive, rather than the negative. For women especially this herb and it's association with the Five of Cups ties in strongly with our menses. The spilled cup (monthly period) may signify that conception has not yet been achieved, but this shouldn't be your focus. You should look to the other cups for love, hope and support for the next coming cycle.
A herb ruled by Saturn, this herb is also helpful in rites where you wish to let go, and once again the strong feminine energy from Horsetail makes it excellent as a tool for women who are having difficulty entering or accepting their Crone stage. Horsetail is most powerful *after* it's fertile state, and so are women!
Associated with our root chakra, it links us to our most primal and basic instincts. In times of loss and bereavement, we often feel that we are stripped of everything, and this is when horsetail is most helpful to us. Horsetail is a herb of new beginnings, and when we feel we have lost everything, this herb can help us start again and rebuild.