(1) The researchers credit L-theanine, an ingredient found in black, green, oolong and pekoe teas - but not in herbal teas, which usually don't contain Camellia sinensis, the one true tea plant.(2) She even stopped shaking after her silver-needle pekoe tea.(3) Orange pekoe tea is not flavoured with orange.(4) The amino acid L-theanine, found in black, green, oohlong, and pekoe teas, stimulated T-cells, the body's first line of defense.(5) Tea that is classified as Pekoe is composed purely of the new flushes of the leaves - a flush being the flower bud plucked with two youngest leaves.