Ae (sometimes represented as X or Xi), is Amhancholl or Eamhancholl, associated with Witch Hazel. This natural astringent is purifying and cleansing. The word Eamhancholl literally translates to "twin of Hazel", so there is a strong connection to C - Coll in the Ogham. When Amhancholl appears, it's usually an indicator that cleansing and purification is necessary or has taken place.
From a purely medicinal standpoint, Witch Hazel has long been used as a cleanser and astringent. Native American tribes turned it into a poultice which was used to treat swelling and tumors. Amongst the early settlers, midwives arriving in the New World found that it could be used to prevent sepsis following childbirth or an abortion. Today, it's still in use as a treatment for skin inflammations, such as insect bites, mild burns, and even hemorrhoids.
Mundane Aspects: When this symbol appears, it means it's time for a cleansing. Sometimes this is a physical cleansing of our Self, but often it applies to emotional clutter and baggage. Smudge your home, get rid of all the negative energies around you, and allow yourself to purify both your body and your mind.
Magical Aspects: This is a good indicator that you need to do a re-evaluation of your spiritual life. Are you studying things that no longer interest you? Are you hanging on to books or other magical items that you know you'll never need -- or worse, that you really dislike? If you're feeling stagnant, or that you're drifting a bit on a spiritual level, when this symbol appears it probably means you need to rethink your priorities. What are your spiritual goals? Do a cleansing ritual, and help yourself begin anew.