Those kinds of capitate glandular trichomes of S. argentea observed
here (capitate type I, II, III) corresponded to three
types of capitate trichomes described by Werker et al.
(1985a) in their study of some Lamiaceae species in-
cluding Salvia.Serrato-Valenti et al. (1997) observed
two types of capitate glandular trichomes in S. aurea,
which occurred in S. argentea as type I and III.In
Nepeta racemosa L. (Bourett et al. 1994) and S. au-
rea (Serrato-Valenti et al. 1997), small capitate glands
with two head cells were found. In the peltate trichomes of Salvia argentea, the se-
cretory product remained trapped between the cutic-
ular sheath and the head cells, following a pattern al-
ready described for other aromatic Lamiaceae (Bosa-
balidis & Tsekos 1982; Werker et al. 1985a,b; Bruni &
Modenesi 1983; Bourett et al. 1994).From a functional point of view, Werker (1993) classi-
fied the glandular hairs into two types, according to dif-
ferent mode and timing of secretion; a) short-term glan-
dular trichomes, which start and end secretion rapidly;
b) long-term glandular trichomes, in which secretory
material is accumulated in a large subcuticular space.The rupture of
the cuticular sheath is likely, in accordance with As-
cens~ao et al. (1995), who stated that external factors
such as high temperatures, low air humidity or animal
aggression may cause the cuticular rupture.Another
less common mechanism of release has been observed
in peltate trichomes of Salvia argentea, as the droplets
of secretory material were observed on the external sur-
face of the head, which appeared to pass through the
cuticular layer.Some Lamiaceae secre-
tion from capitate trichomes contains mostly polysac-
charides and only small quantities of essential oil.Furthermore,
Werker et al. (1985b) reported that the different mor-
phological structure of some capitate trichomes might
correspond to the production of the different materials.In our study, the cap-
itate trichomes with a bicellular head had a 1-3 celled
stalk or no stalk cell, while bicellular headed capitate
trichomes in S. sclarea (Ozdemir & S ? ,enel (1999,
2001) are the first authors to report the base cell num-
ber of capitate glandular trichomes in the Salvia.The cap-
itate trichomes of S. argentea had 1-7 celled base, while
they had 1-2 celled base in S. sclarea and S. forskahlei
(Ozdemir & S ? ,enel 1999, 2001).On
the other hand, the peltate trichomes are considered
the site of production and storage of essential oil (Bini
Maleci et al. 1983; Werker et al. 1985a).,enel 1999) had no
stalk cell and those in S. forskahlei (Ozdemir & S ?In the
present study, we also determined the base cell number
of capitate glandular trichomes of S. argentea.The morphology of glandular hairs is often related
to the kind of secreted product.Ozdemir & S ?