Lectotypification of the name Crocus sativus var

Peruzzi & al. • Lectotypification of Crocus vernus
TAXON 62 (5) • October 2013: 1037–1040
Lectotypification of the name Crocus sativus var. vernus L. (Iridaceae)
and its consequences within Crocus ser. Verni
Lorenzo Peruzzi, Angelino Carta & Fabio Garbari
Department of Biology, Unit of Botany, University of Pisa, Via Luca Ghini 13, 56126 Pisa, Italy
Author for correspondence: Lorenzo Peruzzi, [email protected]
Abstract The typification of the Linnaean name Crocus sativus var. vernus is discussed. A lectotype is designated from the
Burser Herbarium at UPS. Due to changes in taxonomy and this lectotypification, it has not been possible to maintain the present strict usage of the name. Crocus vernus (L.) Hill should correctly be applied to the plants previously known as C. vernus
subsp. albiflorus (Kit.) Ces. (≡ C. albiflorus Kit.). The next available name for the species to which the name C. vernus subsp.
vernus has been misapplied is C. neapolitanus (Ker Gawl.) Loisel.
Keywords Crocus; Crocus ser. Verni ; Linnaeus; nomenclature; taxonomy; typification
Received: 12 Oct. 2012; revision received: 17 Apr. 2013; accepted: 18 June 2013. DOI: http://dx.doi.org/10.12705/625.7
INTRODUCTION
Crocus L. (Iridaceae) belongs to the tribe Croceae, together with other bulbous genera such as Gladiolus L. and
Romulea Maratti (Goldblatt & al., 2008). Crocus includes
about 100 species (Kerndorff & Pasche, 2011; Peruzzi & Carta,
2011; Harpke & al., 2012; Ranđelović & al., 2012). According
to Mathew (1982) it is subdivided into two subgenera: Crocus
subg. Crocus and C. subg. Crociris B. Mathew. The former is
further split into two sections and many series. Within Crocus
sect. Crocus, there is C. ser. Verni B. Mathew, which includes
many taxonomically critical taxa and is typified by Crocus
vernus (L.) Hill., a name still lacking a formally designated
type (Jarvis, 2007). The aim of this paper is to fix the application of the name Crocus sativus var. vernus L., fundamental
for further systematic studies in Crocus ser. Verni.
TYPIFICATION OF CROCUS SATIVUS VAR.
VERNUS
Linnaeus (1753), in the protologue, cited explicitly Bauhin
(1623). Bauhin’s polynomials are linked with original material
studied by Linnaeus in the Burser Herbarium in UPS (Stearn,
1957; Jarvis, 2007). In this herbarium are five specimens
labelled as “Crocus vernus latifolius”: (1) “Ex Horto Leydensi ”
(III: 63 post), with a well-preserved but incomplete (lacking bulb
tunics) individual of unknown natural origin; (2) “In Gothardo
Rhaetorum” (III: 64), with three well preserved and complete individuals from a well-defined geographic area; (3) “Basileae in
horto Heinzmanni ” (III: 67), with three incomplete individuals
of unknown natural origin; (4) “Annaebergae in horto meo. Sed
bulbum acceperam a D. Lud. Jungermanno” (III: 68); and (5)
“Ex Horto Leydensi ” (III: 68 post), each with a well-preserved
and complete individual of unknown natural origin. All these
specimens can be considered as part of the original material.
Moreover, the Linnaean Herbarium (LINN!) contains one
sheet (56.1; numbering follows Savage, 1945) which is marked
“1. β sativus” manu Linnaeus, and can also be considered as
original material for the name, because of the direct link to the
variety β (image: http://www.linnean-online.org/768).
The original material in the Burser Herbarium is very heterogeneous. Hence it is evident that Linnaeus’s circumscription
of Crocus sativus var. vernus included several early-flowering
crocuses, currently recognized as different species.
Individuals in III: 67 are very incomplete and it is impossible to infer their precise identity following modern concepts; III: 68 and III: 68 post seemingly represent the same
yellow-flowered unit (possibly belonging to Crocus ser.
Flavi B. Mathew), which is very distant from the traditional
application of C. vernus. Thus, all of these were excluded from
the choice of lectotype.
Sheet III: 63 post lacks bulb tunics and a definite geographical provenance is not given. Thus, this specimen cannot
be positively identified; it may represent a plant falling within
the traditional concept of Crocus vernus, but it might also represent a taxon not belonging to Crocus ser. Verni. Hence, an
eventual selection as lectotype would result in future taxonomic
uncertainties and subjective judgements. This problem cannot
be solved by selecting a supporting epitype because within the
current circumscription of C. vernus subsp. vernus (Mathew,
1980, 1982) at least three systematic units are included: (1)
one, for which the name C. heuffelianus Herb. is available,
widespread from Balkans to East Europe (2n = 12, 18, 19, 20,
21, 22, 23); (2) one, for which the name C. neapolitanus (Ker
Gawl.) Loisel. is available (see discussion below), occurring
in the central Mediterranean (2n = 8); and (3) one, so far included within C. vernus, presently lacking a formal taxonomic
recognition and seemingly widespread in northwestern Italy
(2n = 16). Which of these units should be selected to serve as
epitype? It is evident that any choice would be arbitrary and
there would be serious doubt as to whether the lectotype and
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Peruzzi & al. • Lectotypification of Crocus vernus
epitype represented the same taxon. Specimen 56.1 in LINN
(albeit likely conspecific with III: 64) is of unknown origin and
presents the same problem as III: 63.
Accordingly, we select the herbarium sheet III: 64 in the
Burser Herbarium (UPS) as the lectotype of C. sativus var.
vernus. Our choice does not strictly correspond with the current
concept of the name Crocus vernus, so far applied to plants with
flowers predominantly blue-violet and style mainly overtopping
stamens (e.g., Mathew, 1982). On the contrary, there is a complete correspondence with the plants occurring in the mountains
of southern Europe currently known as Crocus vernus subsp.
albiflorus (Kit.) Ces. (≡ Crocus albiflorus Kit.) marked by flowers predominantly white and style deeply inserted within the
stamens (Mathew, 1982). This was also largely confirmed by
field surveys in the—from now on—locus classicus of C. ver­
nus (the San Gottardo area, in Ticino, Switzerland), in spring
2012 (Fig. 1). It is also interesting to note that Mathew (1982),
despite applying the name to long-styled plants, cited as type
locality “Switzerland”, evidently deriving this information from
Hill (1765: “native of Switzerland”). Switzerland is apparently
a portion of locus classicus citation in the Linnaean protologue
(“Habitat in Alpibus Helveticis …”). Indeed, in recent floristic
surveys of Switzerland only short-styled, predominantly white
plants are known (Aeschimann & al., 2004; Lauber & Wagner,
2007, in both cases under the name C. albiflorus).
TAXON 62 (5) • October 2013: 1037–1040
By studying topotypical Swiss material, it was also possible to establish the chromosome number, 2n = 8 (Fig. 2). As
the morphological features, the diploid idiogram well agrees
with the karyograms reported by Brighton (1976, under the
name C. albiflorus), obtained from plants collected in Austria,
N Italy and Slovenia: they are marked by homologous couples
with apparent (especially the first and the latter) structural
heterozygosities.
Crocus vernus (L.) Hill, Veg. Syst., ed. 1, 10: 1765 ≡ Crocus
sativus var. vernus L., Sp. Pl.: 36. 1753 – Lectotype (designated here): [Switzerland, Ticino] In Gothardo Rhae­
torum, Burser Herbarium III: 64 (UPS [digital image!]).
— Figure 3.
NOMENCLATURAL CONSEQUENCES
As a result of our lectotypification of Crocus sativus var.
vernus, Crocus albiflorus Kit (≡ Crocus vernus subsp. albiflo­
rus (Kit.) Ces.) becomes a heterotypic synonym of C. vernus
(L.) Hill. Therefore, another name must be applied to the material that has been known as Crocus vernus or Crocus vernus
subsp. vernus. We conclude that the oldest available name, at
species level, for this taxon is C. neapolitanus (Ker Gawl.)
Fig. 1. Flowers of Crocus vernus (L.) Hill from topotypical populations (Swiss Alps, Ticino, Airolo, San Gottardo area, 1100–1500 m a.s.l.,
31 March–1 April 2012; herbarium specimens deposited in PI), expressing the whole range of chromatic variation of tepals. Flowering individuals bear white as predominant colour in more than 90% of cases. — Photographs by L. Peruzzi.
1038
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Peruzzi & al. • Lectotypification of Crocus vernus
TAXON 62 (5) • October 2013: 1037–1040
Loisel. Later isonyms are Crocus neapolitanus (Ker Gawl.)
Ten. ex Hoppe in Flora 1: 588. 1818 and Crocus neapolitanus
(Ker Gawl.) Ten., Semina: 11. 1825 (and not Cat. Hort. Neapol.
1813: 11. 1815, as it appears in www.ipni.org, since in that publication no Crocus name at all is present).
We do not view the nomenclatural changes resulting from
our lectotypification of Crocus sativus var. vernus to be disadvantageous and avoided by proposing to conserve the type of
Crocus sativus var. vernus. Flora Europaea (Mathew, 1980)
and Mathew’s (1982) Crocus monograph circumscribed Crocus
vernus broadly, the short-styled white-flowered populations
being treated as a subspecies (C. vernus subsp. albiflorus).
Hence, what was C. vernus subsp. albiflorus is now C. vernus
subsp. vernus and what was C. vernus subsp. vernus actually
includes three systematic units, each to be recognised as species (D. Harpke & al., in prep.). Thus, nomenclatural stability
was not possible under any scenario. Moreover, our choice has
the advantage to definitely fix the application of the Linnaean
name, without any identification ambiguities.
Fig. 3. Lectotype of the name Crocus sativus var. vernus L. at UPS (In
Gothardo Rhaetorum, Burser Herbarium III: 64).
TYPIFICATION OF CROCUS NEAPOLITANUS
Fig. 2. Crocus vernus (L.) Hill, microphotographs of four metaphasic
plates (top) and diploid idiogram (bottom) obtained from plants collected in locus classicus (see caption of Fig. 1 for more information).
Mean chromosome length ranges from 3.8 to 9.5 µm. The karyological protocol used is described in Peruzzi & Carta (2011). — Scale bars
= 10 µm.
Crocus neapolitanus (Ker Gawl.) Loisel. in Herb. Gén. Amateur 2: [101]. 1817 (“napolitanus”), non Hoppe 1818 ≡ Cro­
cus vernus var. neapolitanus Ker Gawl. in Bot. Mag. 22:
t. 860. 1805 – Lectotype (designated here): illustration
in Bot. Mag. 22: t. 860. 1805. — Figure 4.
This species, described from Naples area in southern Italy
(Sims, 1805), is diploid, marked by 2n = 8 chromosomes, and
it is widespread in SE France, Italy, SW Austria and Slovenia
(Brighton, 1976; Aeschimann & al., 2004, in both cases under
the name C. vernus).
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LITERATURE CITED
Fig. 4. Lectotype of the name Crocus vernus var. neapolitanus Ker
Gawl. (in Bot. Mag. 22: t. 860. 1805).
ACKNOWLEDGEMENTS
We are most grateful to Dr. Mats Hjertson, the Curator of UPS
Herbarium, for help with original material for the name Crocus sativus
var. vernus, to Ernst Bertschi for help in field survey logistics in Switzerland and to Charlie E. Jarvis (London) and Gerry Moore (Greensboro) for helpful and constructive comments on the manuscript.
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