Page 9 - 2009 Prospero hierae Phyton (1)

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The palisade tissue is not uniformly arranged; in fact, it is laterally made
by two-layered cylindrical cells, by one-layered cylindrical cells in the
adaxial face and by small and numerous subcircular cells in the abaxial
side. The spongy tissue is compact with cells of different size. Five vascular
bundles take place in the central part of the spongy tissue. Whereas the
leaf cross section of the Sicilian populations of P. autumnale s. l. (Fig. 3B)
is characterized by a sub-circular outline with 11 well developed ribs, a
strongly concave adaxial face, and one-layered uniform palisade tissue
made of cylindrical cells.

3.4. Distribution and Ecology

P. hierae was exclusively found at Marettimo (Egadi Archipelago, W
Sicily) where it grows on rocky stands very dose to the sea. This small
geophyte is quite rare on the island and it colonizes Mesozoic limestone
characterized by small hollows covered by a feeble layer of soil. It is a
member of ephemeral sub-halophilous communities characterized by rare
or very specialized therophytes such as Senecio incrassatus Guss., Hyme-
nolobus revelieri (JORD .) BRULLO subsp. sommieri (PAMP) BRULLO, Sagina
maritima G. DoN, Silene sedoides POIRET, Bellis annua L., Catapodium
balearicum (WILLK.) SCHOLZ, Parapholis incurva (L.) H UBBARD, etc.

3.5. Taxonomic Remarks

P. hierae, due to its small size, is quite well differentiated from the
other species belonging to the genus Prospero, but for some morphological
features, such as few-flowered inflorescence, small flowers, and narrow
leaves, it seems to be more related toP. corsicum (BOULLU) J . M. TrsoN from
Corse and Sardinia, P. pulchellum (MUNBY) SPETA from N. Africa, and P.
minimum SPETA from Crete (see Tab. 2). In particular, P. corsicum differs
from P. hierae in having smaller bulbs, flowers , pedicels, tepals , ovary,
stamens and capsule , as well as shorter, green, subcylindrical leaves. As
concerns P. pulchellum, it is differentiated by few, green, narrower leaves,
smaller tepals, stamens and ovary. Finally, P. minimum is characterized by
smaller bulbs, ovary and capsule, longer, narrower and subcylindrical
leaves, pink and larger tepals. Besides, P. hierae is well differentiated from
the other Sicilian populations probably referable to P. autumnale s. l. In
order to highlight the morphological relationships between these species,
an iconography of a diploid population with 2n = 14, coming from Trapani
(W Sicily) and belonging to P. autumnales s. l., is provided (Fig. 3B, 4).
According to literature (KER-GAWLER 1806, STEINHEIL 1834, BAKER 1873 ,
MAIRE 1958, SPETA 1982 , 1998, CONTANDRIOPOULOS & ZEVACO-SCHMITZ
1989), the typical populations of P. autumnale s. str. are characterized by
big bulbs, leaves green, numerous, filiform, up to 35 cm long, stems erect,
up to 35 cm long, inflorescence loose and many flowered, tepals 4.5-5 mm