Folia Geobotanica 33: 103-108, 1998

A NEW POLYPLOID SClLLA (LILIACEAE) FROM THE CRETAN AREA (GREECE)

Dimitris Tzanoudakis 1) & Zaharias Kypriotakis 2)

1) Division of Plant Biology, Department of Biology, University of Patras, GR-265 O0 Patras, Greece; fax +30 61 997279, E-mail tzan2711@otenet.gr

2) Technological Education Institute of Eraklion, School of Agricultural Technology, Stavromenos, PO. Box 140, GR-71110 Eraklion, Greece;fax +30 81 318204

Keywords: Chromosome number, Greek flora, Island flora, Liliaceae, New species, Polyploidy, Scilla talosii

Abstract: Scilla talosii TZANOUDAKIS et KYPRIOTAKIS from the islet of Dia is described as a new species. It is an antumn-flowering taxon related to Scilla autumnalis L. and S. obtusifolia POIRET but distinct morphologically and cytologically from both these taxa. S. talosii is polyploid with 2n=ca. 150 chromosomes.

INTRODUCTION

Dia is one of the larger islets of the Cretan area and lies ca. 25 km NNE of the city of Eraklion. The islet is well known botanically and houses a number of critical Aegean endemics. Some of them, such as Carlina diae (RECH. f.) MEUSEL et KASTNER, have their original type localities here.

A new species, Scilla talosii, of the subgenus Prospero (SALISB.) CHOUARD. has been found on Dia. Scilla talosii is distinguished from the related S. obtusifolia POIRET and S. autumnalis L. by both morphological and cytological characters and was found to be a high polyploid with 2n-ca. 150. A detailed karyotype analysis is in progress.

MATERIAL AND METHODS

Bulbs were collected in the type locality and cultivated in the experimental gardens at the University of Patras and Eraklion. For karyological study, root-tips were pre-treated in a saturated solution of ~x-bromonaphthalene and the chromosomes stained as described by TZANOUDAKIS et al. (1991). Male fertility has been counted in three individuals in cultivation and is estimated as a percentage of the pollen stainability by cotton blue.

RESULTS

The new species described belongs to the Scilla autumnalis group, which according to SPETA (1982) constitutes a distinct genus (Prospero SALISB.). This generic name has not yet been adopted by botanists working in the Greek area and we use the generic name Scilla, until the thorough revision of the genus for the Flora Hellenica is completed.

104 D. Tzanoudakis & Z. Kypriotakis

Fig. 1. Scilla talosii TZANOUDAKIS et KYPRIOTAKIS, holotype (UPA).

Scilla talosiiTZANOUDAKIS et KYPRIOTAKIS spec. nova (Fig. 1-2) Holotypus: Greece, Cretan area, Prov. Eraklion, islet Dia ca. 25 km NNE of the city of

Eraklion, on limestone cliffs. Z. Kypriotakis. 22.XI.1991 (UPA). Bulbus late ovoideus 3.5-4.5 cm longis, 3-3.5 cm diametro; tunicis externis brunneis,

tunicis internis albidis. Folia 2-5 hysteranthia, ensiformia vel anguste elliptica, obtusa; semper scapo breviora 12-15 (-20) cm longa, 2-3 (-3.4) cm lata. Scapus 1-2 (-3), 25-35 cm longus. Inflorescentia autumnalis, racemosa, (15-) 20-25 (-30) flores, primo densiflora, postea laxiflora, rachidi (8-) 10-12 (-15) cm longis; pedicelli floriferi erecti 1-2 cm, pedicelli fructiferi arcuati 3-4 cm longi. Perigonium campanulatum, albo-lilacinum. Perigonium phylla elliptica vel obovata obtusa, interna 5-6 (-6.5) x 2 mm, externa paulo latiora 5-6 (-6.5) x 2-2.4 mm. Stamina tepalis breviora, filamentis albis, simplicibus 4-4.5 mm. Ovarium sessile, album vel albo-purpureum, ovatum, ca. 3 x 2 mm; Stylus albus 2-2.5 mm longus. Capsula subglobosa 5-6 mm in diametro. Semina nigra 3 • 2 mm. Chromosomatum numerus 2n=ca. 150.

Floret Octobris ad med-Novembrium.

A new polyploid Scitta from the Cretan area 105

f . S c m

Fig. 2. Scilla talosii. Flower, perianth segments, capsule and seed: Inner (A) and outer (B) views of flower. Inner and outer view of the outer (C) and inner (D) perianth segments. E & F: capsule and seed, respectively.

Eponymy According to Cretan mythology Talos was a bronze giant (robot) which Dias (Zeus), king

of the Gods, sent as a present to the king of Crete and his son, Minos, in order to guard the island.

Ecology Scilla talosii occurs on rocky slopes and limestone cliffs of the islet of Dia. Two populations,

about 3 km apart, have been found. Both consist of a few individuals and approximately 30 plants have been found in total. In both localities Scilla talosii grows together with Muscari dionysicum RECH. f. and some other Cretan endemics, e.g. Campanula creutzburgii GREUTER, Sedum praesidis RUNEMARK et GREUTER, Petromarula pinnata (L.) DC., Lutzia cretica (L.) GREUTER et BURDET, Carlina diae (RECH. f.) MEUSEL et KASTNER.

106 D. Tzanoudakis & Z. Kypriotakis

fJft fl| ofl i i i I l O p m i

Fig. 3. SciUa talosii: A - mitotic metaphase plate; B - Partial karyograrn with the ten different chromosome types recognized.

Karyology In the material of Scilla talosii studied, an unusually high chromosome number (2n=ca.

150) was found. This suggests a correspondingly high level of polyploidy which seems to be uncommon not only in Aegean endemics (MONTMOLLIN 1982, 1984, TZANOUDAKIS 1986, TZANOUDAKIS et al. 1991) but also within the genus Scilla. The highest chromosome number, so far known, in related species of Scilla is 2n--70 (SPETA 1993). Karyotypic analysis, however, has proved problematic. Based on chromosome morphological characters (centromeric position, presence of nucleolar organizers), groups of metacentric (m), submetacentric (sm), subtelocentric (st), telocentric (t), and SAT - chromosomes (sm B) have been recognized in the metaphase plates of Scilla talosii (Fig. 3B). Within the above mentioned groups chromosome size differentiation is observed, and the different chromosome types are not represented at metaphase plates by the same number of chromosomes. Thus, the basic chromosome number and the ploidy level remain uncertain.

Taxonomic relationships The difficulties related to the taxonomy of the autumn-flowering Mediterranean

representatives of the genus Scilla have been fully discussed by SPETA (1993). Scilla talosii,

A new polyploid Scilla from the Cretan area 107

Table 1. Morphological and karyological differences among Scilla talosii, S. autumnalis and S. obtusifolia

Character S. autumnalis S. obtusifolia S. talosii

Leaves Narrowly linear or subfiliform, Linear lanceolate 40-150 x 1-2 (-4) mm 30--40 x 5-10(-25) mm

Pedicels Up to 15 mm Up to 15 mm

Perianth Pinkish-blue to lilac, 3-5 mm Pinkish to pinkish lilac, segments in length and -+ similar in width 3-5 mm in length

and -+ similar in width

Sword-like to narrow elliptic 120-150 (-200) x 20-30 (-34) mm

Up to 40 mm

Whitish-lilac, 5-6 (-6.5) mm in length, the inner +- obovate the outer + elliptic, wider than the inner ones

Chromosome 2n=10,12,14,28,42,56,70 2n=8 (x=4) 2n=ca. 150 (x=?) number (x=5,6,7)

characterized by its broad leaves, about 3 cm wide and its high chromosome number (2n=ca. 150), increases the complex morphological and cytological diversity of this group. This combination of characters does not occur in Scilla autumnalis or in N. obtusifolia. In S. autumnalis the leaves are narrowly linear, occasionally up to 4 mm, (MCNErLL 1980) and the karyotype consists of 2n=10, 12, 14, 28, 42, 56, or 70 chromosomes (SPETA 1979, MCNEILL 1980, PARKER et al. 1990, TZANOUOArdS et al. 1991) while S. obtusifolia, which is also characterized by broad leaves, up to 2 cm wide, is diploid with 2n=2x=8 (PASTOR 1985, TZANOUDAKIS, unpubl, data), and distributed in the west Mediterranean (Tab. 1). S. talosii is a more robust species shown for example in the length of the pedicels and perianth. Moreover, in S. talosii the outer perianth segments are wider than the inner ones, a differentiation unknown in S. autumnalis or in S. obtusifolia, while the colour is pale whitish-lilac and not pinkish-lilac as in S. obtusifolia and often in S. autumnalis. S. autumnalis in Crete flowers early (August-September) while S. talosii is in full bloom almost a month later (October-November). Such ecological differentiation probably plays an important role in the reproductive isolation of the taxa concerned.

D I S C U S S I O N

S. talosii is characterized by its broad leaves, a character which suggests affinities with S. obtusifolia, another autumn-flowering taxon recorded from the African and European coasts of the western Mediterranean area. It is well known that most Greek Aegean endemics are considered as relict elements of an old Aegean or Mediterranean flora (GREUTER 1979, TZANOUDAKIS 8s KYPRIOTAKIS 1993) and S. talosii should be considered a further example of such a case. S. talosii, however, is not diploid, a state often encountered in relict elements of the Aegean flora (MONTMOLLIN 1984, TZANOUDAKIS 1986, TZANOUDAKIS et al. 1991), but is a polyploid with an unusually high chromosome number and, presumably, level of polyploidy for the genus Scilla. Although the karyotype analysis of the species is still in progress, S. talosii seems to behave as a stable species since male fertility was found to be very high (> 95%) in all the individuals examined. Thus, it is unlikely to be a recent species. Rather its ecological

108 D. Tzanoudakis & Z. Kypriotakis

characteristics (such as autumn-flowering, member of the insular and/or chasmophytic communities) indicate a relict Mediterranean status (BRuLLO et al. 1989, TZANOUDAKIS & KYPRIOTAKIS 1993, IATROU & TZANOUDAKIS 1995). As is suggested by the above-mentioned recent floristic studies, the autumn-flowering species of the Greek insular flora are under-collected and as a consequence, the floristic diversity is underestimated. The case of S. talosii illustrates this: it is known that the island of Dia has been studied by several botanists (e.g. Sieber and Rechinger), but no one had recognised the existence of the species described here. S. talosii may have been misidentified as Muscari dionysicum which grows side by side with it and which has leaves of similar appearance. The flowers of these two species are easily distinguisable but do not appear at the same time.

Acknowledgements: Financial support by the Greek Secretariat of Research and Technology and the Ministry of Environment and Public works is gratefully acknowledged. The authors also thank Dr. Kit Tan for her critical comments on the manuscript.

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Received 28 July 1997, accepted 26 January 1998