Cucurbitaceae Juss.

First published in Gen. Pl. [Jussieu] 393. 1789 [4 Aug 1789] (1789)nom. cons.
This family is accepted

Descriptions

Taylor, N. & Zappi, D. (2009). Neotropical Cucurbitaceae.

Morphology
Description

Climbing or scrambling vines, sometimes woody lianas, rarely decumbent shrubs, almost never self-supporting; tendrils originated from branches and alternate to the leaves, often branched, sometimes absent. Stipules absent. Leaves generally petiolate , sometimes scabrous , generally with foetid or rank smell, venation generally palmate , entire to lobed , sometimes compound , margin entire , crenate or dentate , base often cordate , with a broad sinus . Inflorescences axillary , racemose or paniculate, rarely subumbellate (Gurania Cogn.), often reduced to a showy, solitary flower . Flowers unisexual in dioecious or monoecious plants, radially symmetric , epigynous ; calyx (3-)5- merous , lobes fused or free ; corolla (3-)5- merous , lobes fused or free , white, cream, yellow, orange, rarely red or pink; stamens (1-)3-5, fused to the hypanthium and adnate or free , anthers dehiscing longitudinally; ovary inferior, placentation parietal , less commonly basal or apical, style present, normally one, generally stout, sometimes 3, stigmas bifid. Fruit normally a hard-skinned berry known as a pepo, green, white, yellow, orange or tinged with red, often spotted or striped, sometimes soft-walled, small berries (Melothria L., some Cayaponia Silva Manso), sometimes fleshy capsules with irregular, explosive dehiscence (Cyclanthera Schrad., Ecballium A.Rich.), rarely capsular or samaroid, 1-many seeded; seeds generally tear-shaped and flattened, but sometimes with irregular margins and varied ornamentation, embryo oily and endosperm lacking.

General Description
Notes on delimitation
  • Together with the Begoniaceae, Cucurbitaceae is currently placed within order Cucurbitales (APG II, 2003, Souza & Lorenzi 2005).
General notes
  • Easy to recognize at family level, the difficulties of determining Cucurbitaceae to genus and species are mainly caused by their unisexual flowers borne in different types of inflorescences (female flowers tend to be large, solitary and axillary, while the male inflorescences are racemose or paniculate and the flowers are smaller and early deciduous).
  • Matching specimens with female flowers, male flowers and fruit has always been a challenge and authors provide keys for flowering AND fruiting specimens (Jeffrey & Trujillo 1992).
  • The family was radically revised by Jeffrey (1980), who subdivided it in two subfamilies Cucurbitoideae and Zanonioideae based on fusion of stigmas and tendril morphology.
  • Cucurbitoideae has been further subdivided into tribes.
  • Due to its economic importance, the genus Cucurbita has been studied in detail from the point of view of its domestication (Nee 1990).
Number of genera

Neotropical:

  • Abobra tenuifolia Naudin, cultivated as ornamental.
  • Apodanthera Arn. 15 spp.
  • Calycophysum Karst. & Triana 6 spp.
  • Cayaponia 45 spp.
  • Ceratosanthes Burm. ex Adans. 1 sp.
  • Cucurbita L. 27 spp., C. pepo (squashes and marrows), C. maxima (pumpkin), C. moschata (butternut squash).
  • Cucurbitella Walp. 2 spp.
  • Cyclanthera 15 spp.
  • Doyerea Grosourdy1 sp.
  • Echinopepon Naudin 12 spp.
  • Elateriopsis Ernst 6 spp.
  • Fevillea L.7 spp.
  • Gurania 1 sp.
  • Helmontia Cogn. 1 sp.
  • Melancium Naudin 1 sp.
  • Melothria 10 spp.
  • Melothrianthus Mart.Crov. 1 sp.
  • Posadaea Cogn. 1 sp.
  • Pseudocyclanthera Mart.Crov. 1 sp.
  • Pseudosicydium Harms 1 sp.
  • Psiguria Neck. 15 spp.
  • Pteropepon Cogn. 3 spp.
  • Rytidostylis Hook. & Arn. 5 spp.
  • Sechium P.Browne 5 spp., S. edule (Chayote or Chuchu)
  • Selysia Cogn.3 spp.
  • Sicana odorifera Naudin, edible fruit known as Cruá.
  • Sicydium Schltdl. 6 spp.
  • Sicyos L. 25 spp.
  • Siolmatra Baill. 3 spp.
  • Wilbrandia Silva Manso 2 spp.

Introduced:

  • Benincasa hispida (Thunb.) Cogn. - cultivated.
  • Citrullus lanatus (Thunb.) Matsumura & Nakai - watermelon.
  • Cucumis pepo Dumort. - cucumber.
  • Ecballium elaterium (L.) A.Rich. - squirting cucumber.
  • Lagenaria siceraria (Molina) Standl. - bottle gourd or calabash.
  • Luffa aegyptiaca Mill. - luffa or vegetable sponge.
  • Momordica charantia L. - invasive.
  • Peponopsis spp. Naudin - naturalized.
  • Trichosanthes spp. L. - naturalized.
Status
  • Approximately 120 genera and 760 species with mostly tropical distribution, as they do not tolerate sub -zero temperatures.
  • Of these, around 30 genera and over 400 species occur in the Neotropics.
  • Cultivated genera of Neotropical origin (Cucurbita) and introduced ones (Cucumis L., Citrullus Schrad.) are of major importance as food and forage crops.
  • Some species, such as Momordica charantia, are invasive.
Distribution
Distribution in the Neotropics
  • Widely distributed in the Neotropics, represented by over 30 native genera and 8 introduced (see below).
Diagnostic
Distinguishing characters (always present)
  • Plants never self-supporting.
  • Leaves palmate, lobed to dissected.
  • Ovary inferior.
  • Flowers unisexual.
  • Placentation parietal, rarely basal or apical.
Other important characters
  • Climbers or scramblers with tendrils.
  • Leaves with broad sinus and cordate base.
  • Fruit a pepo (a hard-shelled berry with developed endocarp and placenta).
Key differences from similar families
  • Differs from Begoniaceae in climbing habit, presence of tendrils and bilaterally symmetric leaves.
  • From other climbers and vines such as Vitaceae, Sapindaceae and Passifloraceae in unisexual flowers and inferior ovary.
Useful tips for generic identification
  • Tendril ramification.
  • Flower size and colour.
  • Fusion and shape of calyx and corolla -lobes.
  • Shape and disposition of stamens.
  • Styles fused or free.
  • Fruit type.
  • Placentation.
  • Number of seeds per fruit.

(Jeffrey & Trujillo 1992, Gentry 1996).

Notable genera and distinguishing features
  • Cucurbita - Showy yellow flowers, ovary many-ovulated, fruit a pepo.
  • Sechium - Small greenish flowers, ovary uniovulated, fruitdrupaceous.
  • Gurania - Forest liana with showy orange/yellow flowers arranged in pseudo-umbels.
  • Cayaponia - Forest liana with cream-coloured flowers, ovary 2-5-ovulated, ovules pendulous, fruit a berry.
  • Cyclanthera - Delicate climber, flowers small and white or cream, fruitclavate and explosive, spiny, seeds ruminated at the edges.
  • Lagenaria Ser. - Flower white, fruit elongated, bottle-shaped.
  • Luffa Mill.- Flowers yellow, medium sized, fruit cylindric, fibrous inside, sometimes operculated.
Literature
Important literature

APG II, 2003. An update of the Angiosperm Phylogeny group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141(4): 399-436.

Gentry, A.H. 1996. A field guide to the families and genera of Woody Plants of Northwest South America (Colombia, Ecuador, Peru). The University of Chicago Press, Chicago and London.

Jeffrey, C. 1980. A review of the Cucurbitaceae. Bot. J. Linn. Soc. 81: 233-247.

Jeffrey, C. & Trujillo, B. 1992. Cucurbitaceae in Flora de Venezuela 5(1): 1 - 201.

Nee, M. 1990. The Domestication of Cucurbita. Economic Botany 44(suppl. 3): 53 - 68.

Souza, V.C. & Lorenzi, H. 2005. Botânica Sistemática: guia ilustrativo para identificação das famílias de Angiospermas da flora brasileira, baseado em APG II. Nova Odessa, Brazil: Instituto Plantarum.

[NTK]

Cucurbitaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

Morphology General Habit
Herbs or rarely undershrubs with watery juice, often scabrid; stems scandent or prostrate; tendrils mostly present, spirally coiled
Morphology Reproductive morphology Flowers
Flowers monoecious or dioecious, very rarely hermaphrodite, actinomorphic Female flower: calyx-tube adnate to the ovary and often produced beyond it; staminodes usually not present; ovary inferior or very rarely free; placentas often 3, parietal but often meeting in the middle; ovules numerous, rarely few, arranged towards the walls of the ovary; style simple or rarely 3 free styles; stigmas thick Male flower: calyx tubular, lobes imbricate or open; corolla polypetalous or gamopetalous, lobes imbricate or induplicate-valvate; stamens free or variously united, mostly 3, rarely 1–5, one anther always 1-celled, the others 2-celled, cells straight or often curved, flexuous or conduplicate, connective often produced
sex Male
Male flower: calyx tubular, lobes imbricate or open; corolla polypetalous or gamopetalous, lobes imbricate or induplicate-valvate; stamens free or variously united, mostly 3, rarely 1–5, one anther always 1-celled, the others 2-celled, cells straight or often curved, flexuous or conduplicate, connective often produced
sex Female
Female flower: calyx-tube adnate to the ovary and often produced beyond it; staminodes usually not present; ovary inferior or very rarely free; placentas often 3, parietal but often meeting in the middle; ovules numerous, rarely few, arranged towards the walls of the ovary; style simple or rarely 3 free styles; stigmas thick
Morphology Reproductive morphology Seeds
Seeds various, often flattened, without endosperm
[FWTA]

Cucurbitaceae, C. Jeffrey. Flora of Tropical East Africa. 1967

Morphology General Habit
Woody or herbaceous mostly with climbing or trailing stems bearing tendrils and often arising from a tuberous rootstock, rarely without tendrils
Morphology Leaves
Leaves alternate, simple and palmately veined or pedately compound with 3–25 leaflets, when simple usually very variable, petiolate Tendrils lateral, stipular in position, usually one at each node, either simple or proximally 2–7-fid and spiralling only above the point of branching, or apically bifid and spiralling above and below the point of branching, rarely reduced to spines or absent
Morphology Reproductive morphology Inflorescences
Probracts (usually small, often glandular, foliar structures) sometimes present at the base of the peduncles
Morphology Reproductive morphology Flowers
Flowers usually unisexual, monoecious or dioecious, axillary, variously arranged, but ? more commonly solitary than ?
Morphology Reproductive morphology Flowers Hypanthium
Receptacle-tube very shallow to elongated-tubular; lobes (3–)5
Morphology Reproductive morphology Flowers Corolla
Petals (3–)5, free or united into a regular or slightly to rarely strongly zygomorphic corolla
Morphology Reproductive morphology Flowers Androecium
Stamens basically 5, alternate with the petals, inserted on the receptacle-tube or on the basal disk, but always modified in one or more ways, giving the following conditions: stamens 5, equidistant or in 2 pairs with 1 single; stamens 4; stamens 3, 2 double and 1 single, free or with the anthers ± united, or with the filaments united into a central column and the anthers free or united; or stamens 2, 1 triple, 1 double; thecae straight, hooked, arcuate, duplicate, triplicate or triplicate and contorted, sometimes the filaments united and the thecae horizontal, forming a central equilateral triangle, split ring or continuous ring; staminodes often present in ? flowers
Morphology Reproductive morphology Flowers Gynoecium
Ovary usually inferior, generally 1-locular, composed of (2–)3(–5) united carpels or rarely of 1 carpel only; placentation parietal or rarely axillary, sometimes apical, basal or apical and basal, sometimes obscured by the often large placentas; ovules anatropous, 1–many, horizontal, pendulous, or ascending; style 1, with usually 3 bilobed stigmas or stigma-lobes, or styles (2–)3, each with 1 bilobed stigma
Morphology Reproductive morphology Fruits
Fruit a dry or fleshy capsule, berry or hard-shelled pepo, indehiscent or dehiscent by valves, an operculum, slits or apical pores or irregularly, or rarely samaroid, smooth or variously ornamented, 1–many-seeded, sometimes very large
Morphology Reproductive morphology Seeds
Seeds large, commonly compressed, sometimes winged; embryo large; endosperm absent
[FTEA]

Cucurbitaceae, C. Jeffrey. Flora Zambesiaca 4. 1978

Morphology General Habit
Scandent or prostrate tendriliferous annual or perennial herbs or less often woody lianes, rarely erect herbs without tendrils, often with tuberous rootstock
Morphology Leaves
Leaves alternate, palmately veined, simple or pedately compound Tendrils lateral to the petiole base, simple, distally 2-fid or proximally 2–7-fid, rarely reduced to spines or absent, usually 1 at each node
Morphology Reproductive morphology Flowers
Flowers unisexual, epigynous, monoecious or dioecious, axillary, variously arranged, the female commonly solitary. Glandular bract-like structures (probracts) sometimes present at base of peduncles
Morphology Reproductive morphology Flowers Receptacle
Receptacle-tube shallow to tubular, usually 5-lobed, lobes usually small
Morphology Reproductive morphology Flowers Corolla
Petals usually 5, free or variously united, corolla mostly regular
Morphology Reproductive morphology Flowers Androecium
Stamens basically 5, androecium always variously modified, commonly appearing as 2 double stamens and 1 single stamen, free or variously coherent or united; antherthecae often convoluted
Morphology Reproductive morphology Flowers Sterile Parts
Staminodes often present in female flowers
Morphology Reproductive morphology Flowers Gynoecium
Ovary inferior, unilocular or sometimes 3-locular, of usually 3 united carpels; placenta-tion parietal, rarely axillary, placentae often intrusive Ovules anatropous, 1-many, horizontal, pendulous or ascending; style 1, with 2 or usually 3 stigma-lobes, or styles 3
Morphology Reproductive morphology Fruits
Fruit a dry or fleshy capsule, berry or hard-shelled pepo, variously dehiscent or indehiscent, rarely a 1-seeded samara
Morphology Reproductive morphology Seeds
Seeds 1-many, rather large, often compressed, sometimes winged; embryo large; endosperm absent
[FZ]

Sources

  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of West Tropical Africa

    • Flora of West Tropical Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Neotropikey

    • Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.
    • http://creativecommons.org/licenses/by/3.0