|Description of Trichomes:
Glandular secreting trichomes (GST).
A. annua glandular trichomes are 10-celled biseriate. Three apical cell pairs represent the secretory head, the first two top hairs contain amoeboid plastids without thylakoid, whereas in the two cell pairs below, ameboid chloroplasts show the presence of photosynthetic thylakoids. Stalk cell plastids containing starch grains and thylakoids were occasionally present in basal cell.
In A. annua GSTs, the sesquiterpene lactone artemisinin accumulates to levels of 0.01-2% dry weight.
1) Duke SO, Paul RN (1993) Development and fine structure of glandular trichomes of Artemisia annua L.. Int. J. Plant Sci. 154: 107-118.
2) Wagner GJ, Wang E, Shepherd RW. New approaches for studying and exploiting an old protuberance, the plant trichome. Ann Bot (Lond). 2004 Jan;93(1):3-11.
3) Mary V. Duke, Rex N. Paul, Hala N. Elsohly, George Sturtz and Stephen O. Duke. Localization of Artemisinin and Artemisitene in Foliar Tissues of Glanded and Glandless Biotypes of Artemisia annua L. International Journal of Plant Sciences. Vol. 155, No. 3 (May, 1994), pp. 365-372