Lichens and higher plants on stone: a review - AseanBiodiversity.info

Plate 2. (a) Fourteenth century tower of San Giovanni, Elba isl<strong>and</strong>. The same kinds of lichens <strong>and</strong> <strong>plants</strong> grow on the surrounding granite <strong>and</strong> the stones
of the tower, also of local granite. (b) Archof an 18thcentury gate at Vignano, Siena. A cypress about 3 m highis growing between the bricks, to
the detriment of the structure. (c) Crassulaceous plant (Sedum pachyphyllum) originating from a pot plant, growing on a mound of detritus consisting
of moss <strong>and</strong> atmospheric dust at the base of the Altar of the Fatherl<strong>and</strong>, Rome (early twenties). (d) Walls of the town of San Quirico d’Orcia (Siena
Province), hosting a plum tree. The roots of the plant have already dislodged many stones. (e) Two examples of Dittrichia viscosa growing on the
monument to Petrarch in Arezzo. The rhizome of the lower plant has already caused the marble to crack. (f) Ruins of the town of Maktar in Tunisia.
Plants grow mostly in cracks <strong>and</strong> are periodically removed to keep the site accessible to tourists.
3.2. Common <strong>plants</strong> colonizing monuments
Botanists have long been interested in <strong>plants</strong> that grow in
the walls of European towns such as Cambridge (Rishbeth,
1948), Durham (Woodell <strong>and</strong> Rossiter, 1959), Padua (Beguinot,
1912, 1913, 1916a–c), Pavia (Traverso, 1898, 1899),
Florence (Arrigoni <strong>and</strong> Rizzotto, 1994), Rome (Anzalone,
1951), Palermo (Cannarella, 1909, 1912) <strong>and</strong> other continental
towns (Kunick, 1982; Sukopp <strong>and</strong> Werner, 1983). In
a recent study (Lisci <strong>and</strong> Pacini, 1993a, b), we examined
the microsites in which <strong>plants</strong> become established, <strong>and</strong> their
methods of colonization <strong>and</strong> reproduction.