96 – II.2. SQUASHES, PUMPKINS, ZUCCHINIS, GOURDS (CURCURBITA SPECIES)
found on the Yucatan Peninsula). On the other hand, it is common for small farmers in
Latin American to manage, in common plots, a fair representation of races or local
varieties with morphological features similar to those that have been considered specific
to some groups of commercial cultivars. C. pepo accessions are well represented in
genebanks of the Americas (e.g. CIFAP). As with C. maxima and C. moschata,
in addition to the diversity seen in the Americas, multiple centres of diversity exist for
C. pepo, primarily as landraces, around the world.
Morphological characters
Cucurbita is a genus of dicotyledonous flowering plants in the family Cucurbitaceae.
The wild and cultivated species of Cucurbita are trailing or climbing vines, or subshrubs
(bushes) in some cultivated varieties. The cultivated and wild mesophytic species are
annuals or such long-lived annuals to be seen as short-lived perennials. The xerophytic
species are perennials, persisting for years due to their long tap roots. Mature stems are
approximately 1 cm thick, but considerably thicker at the base of the plant. Cultivated
forms have internodes that are usually 15-25 cm long, with petioles having a similar
range of length and leaf laminae that are generally pentagonal in outline, ranging to
30 cm diameter or more. Wild forms have more diminutive vegetative parts. Emerging
from the leaf axil are solitary branched tendrils 20 cm long and solitary flowers. Wild and
cultivated species of Cucurbita are mostly monoecious, i.e. both male and female flowers
are produced by a single plant, the exception being C. foetidissima, where some varieties
are gynomonoecious. The large flowers are gamopetalous with tubular-campanulated
corollas, very showy, light yellow or bright yellow-orange in colour. Rooting commonly
occurs at the stem nodes. Some varieties produce tendrils that help secure vines, limit
wind damage and improve vine growth across weedy and uneven ground.
For purposes of identification, the five domesticated species are differentiated by the
following morphological characteristics: habit of growing, stems, leaves (in distal nodes),
indument (petioles and primary veins in the lower surface of blades), receptacle (in
staminate flowers), corolla, filaments, peduncle of fruit, size and shape of fruit, surface of
fruit, colour of fruit, pulp of fruit, seeds (shape and size), and colour of seeds. Table 2.3
shows only the most outstanding features of the cultivated species. A complete treatment
(descriptions, synonyms, illustrations, distribution maps, etc.) of Cucurbita is available in
Lira, Andres and Nee (1995). Note, however, that cultivated species of Cucurbita are
very diverse locally, regionally and worldwide (e.g. Jeffrey, 1990; Nee, 1990; Lira,
Andres and Nee, 1995; Sanjur et al., 2002), having a wealth of innumerable strains,
landraces and varieties that defy facile description (Esquinas-Alcazar and Gulick, 1983;
Lira, Andres and Nee, 1995). As more plants are considered, the array of variations and
combinations of notable traits increases and the differentiations become less distinct and
meaningful.
This section and Annex 2.A2 offer examples of cultivars available in the retail seed
market (“commercial” cultivars) for four of the five cultivated Cucurbita species;
commercially available cultivars for C. ficifolia are scarcely found, but some are available
online, e.g. from heirloom seed vendors.
