II.2. SQUASHES, PUMPKINS, ZUCCHINIS, GOURDS (CURCURBITA SPECIES) – 85
is known to have very aromatic flowers (Lira, Andres and Nee, 1995). Several Cucurbita
species are used in traditional medicine; as an anthelmintic (Chou and Huangfu, 1960;
Schabort, 1978; Chiej, 1984; Argueta, 1994); to treat benign prostatic hypertrophy (Duke
and Ayensu, 1985; Kreuter, 2000; Gossell-Williams, Davis and O’Connor, 2006); as a
diuretic (Chiej, 1984); as a nerve tonic and to sooth burns, inflammations and boils
(Chopra, Nayar and Chopra, 1956); and as an antihyperglycemic agent (Andrade-Cetto
and Heinrich, 2005; Xia and Wang, 2006). Lira, Andres and Nee (1995) discuss several
of these uses.
Cultivated species of Cucurbita are very diverse locally, regionally and worldwide,
having a wealth of innumerable strains, landraces and varieties (e.g. Esquinas-Alcazar
and Gulick, 1983; Jeffrey, 1990; Nee, 1990; Lira, Andres and Nee, 1995; Sanjur et al.,
2002). It should be noted that commonly used descriptors such as “pumpkin” or “squash”
apply broadly to morphotypes across all of the cultivated Cucurbita, as does the term
“gourd”. Thus, the term “pumpkin” is applied to certain fruits of C. maxima as well as
certain fruits of C. moschata, C. argyrosperma and C. pepo; and the term “squash” is
applied to certain fruits of C. pepo as well as certain fruits of C. maxima, C. moschata and
C. argyrosperma. Similarly, in English the word “pumpkin” or “squash” as used
colloquially could be describing a variety, a subspecies, a species or, at the extreme,
a genus. In order to avoid confusion, this chapter will rely on taxonomic identifiers to the
extent possible.
Taxonomy..............................................................................................................................................
The genus Cucurbita, which is native to the Americas, is in the order Cucurbitales,
the family Cucurbitaceae, the subfamily Cucurbitoideae and the tribe Cucurbiteae
(Jeffrey, 1990). The Cucurbita are not closely related to other Cucurbitaceae genera.
Cucurbita traditionally has been considered a distinct genus of 20-27 species (Bailey,
1943, 1948; Cutler and Whitaker, 1961; Esquinas-Alcazar and Gulick, 1983), which,
due to the ecological characteristics of their habitats and duration of their life cycles, are
divided into two large groups: the xerophytic species, perennials adapted to dry climates
with tuberous storage roots; and the species adapted to moister or mesophytic
environments, either annuals or short-lived perennials with fibrous roots. Within this
second group are the five cultivated species, whose amazing morphological variation –
especially of fruits and seeds – has led to multiple names and classification schemes.
Crossability experiments have more recently revealed that some of the species considered
separate members of the 27-member cohort were merely from different wild populations.
Nee (1990) recognises 12 or 13 species. Lira, Andres and Nee (1995) recognise
15 species and 20 taxa.
The Cucurbita can be categorised into seven groups (Table 2.1): the Argyrosperma
group, the Maxima group, the Pepo group, the Okeechobeensis group, the Digitata group,
the Foetidissima group and a seventh group, those species with no defined group
(i.e. C. ecuadorensis, C. ficifolia, C. lundelliana and C. moschata). The five cultivated
Cucurbita species are listed amongst these seven groups, and highlighted in Table 2.1
in bold.
The cultivated species C. argyrosperma, C. maxima, C. moschata and C. pepo each
are comprised of a large series of convarieties, varieties and forms, including numerous
local races (landraces) or varieties, and commercial cultivars. At least three of the
cultivated species, C. argyrosperma, C. maxima and C. pepo are known to interbreed
