Thanks for the informative post...I'm a noob to but learning as I go. I found this on the web, a more "scientific" way of saying what Zeus is trying to tell us…
The calyxes first appear as single, thin, tubular, green sheaths surrounding an ovule at the basal attached end with a pair of thin white, yellowish green, or purple pistils attached to the ovule and protruding from the tip fold of the calyx. As the flower begins to age and mature, the pistils grow longer and the calyx enlarges slightly to its full length. Next, the calyx begins to swell as resin secretion increases, and the pistils reach their peak of reproductive ripeness. From this point on, the pistils begin to swell and darken slightly, and the tips may begin to curl and turn reddish brown. At this stage the pistillate flower is past its reproductive peak, and it is not likely that it will produce a viable seed if pollinated. Without pollination the calyx begins to swell almost as if it had been fertilized and resin secretion reaches a peak. The pistils eventually wither and turn a reddish or orange brown. By this time, the swollen calyx has accumulated an incredible layer of resin, but secretion has slowed and few fresh terpenes and cannabinoids are being produced. Falling pistils mark the end of the developmental cycle of the individual pistillate calyx. The resins turn opaque and the calyx begins to die. The biosynthesis of cannabinoids and terpenes parallels the developmental stages of the calyx and associated resin-producing glandular trichomes. Also, the average developmental stage of the accumulated individual calyxes determines the maturational state of the entire floral cluster. Thus, determination of maturational stage and timing of the harvest is based on the average calyx and resin condition, along with general trends in morphology and development of the plant as a whole.
More here….
http://www.kindgreenbuds.com/marijuana-grow-guide/cannabis_maturation_harvesting.html