Macula originalis non est in te.

The dogma of the Immaculate Conception was defined ex cathedra by Pope Pius IX in 1854, but the belief itself is ancient, though it was for a long time contested (even by such Doctors of the Church as St. Thomas Aquinas). The feast originated in the East as the Conception of Mary, although in the East today there is no defined dogma of the Immaculate Conception. An Eastern Orthodox man I know said that their issue with the Immaculate Conception has more to do with its dependence on the doctrine of original sin, which is not seen in the same way in the East as in the West. There is that, and also that the East (in schism) does not define any more dogmas after the Seven Ecumenical Councils. This is my understanding of the issue.

St. Anne with the Blessed Virgin and Jesus

Sometimes people mistake "immaculate" to mean something like "miraculous", and think that the Immaculate Conception refers to the conception of Jesus in the Virgin by the Holy Spirit. Tota pulchra es, an ancient, fourth century prayer formed from verses of Judith and Song of Solomon contains the Latin word macula, which means a spot or stain: macula originalis non est in te is "the original stain is not in thee."

My horticultural experience reminds me of what macula means: plants with the epithet maculatus have spots, usually on their leaves. I think of Lamium maculatum, spotted deadnettle, a popular groundcover for shady places. "Maculatus" would make a fine nickname for a freckled friend, although this word can connote pollution and defilement also (which might make it even more apt as a nickname, depending on the person). Curious, I looked up the proper Latin word for freckle, which is lenticula, also the word for lentil. Thus lenticulatus would mean "freckled," though I'm not sure this is proper Latin.

Anyway, immaculata means "spotless," "without stain".

Tota pulchra es (4th Cent.)

Tota pulchra es, Maria.
Et macula originalis non est in Te.
Tu gloria Ierusalem.
Tu laetitia Israel.
Tu honorificentia populi nostri.
Tu advocata peccatorum.
O Maria, O Maria.
Virgo prudentissima.
Mater clementissima.
Ora pro nobis.
Intercede pro nobis.
Ad Dominum Iesum Christum.

Thou art all fair, O Mary.
And the original stain is not in thee. (Song of Solomon 4:7)
Thou art the glory of Jerusalem.
Thou, the joy of Israel.
Thou art the honor of our people. (Judith 15:10)
Thou art the advocate of sinners.
O Mary, O Mary.
Virgin most prudent.
Mother most tender.
Pray for us,
Intercede for us with Jesus Christ our Lord.

Corsican setting of the Tota pulchra es