CHAPTER II 

 SYSTEMATIC BOTANY OF THE CULTIVATED CUCURBITS 



The plant family (Cucurbitaceae) constitutes one 

 of the most interesting assemblages of plants known. f 

 Many of its members develop a tremendous vegetative 

 growth and a remarkable amount of fruit from an 

 apparently insignificant and inadequate root system; 

 and the floral structures have rendered its relationships 

 a matter of debate among botanists ever since a natural 

 system of classification was first attempted." The wide 

 spread of this family through the tropics would indicate 

 a considerable age, but many of the sub-groups seem to 

 show by their extreme variability and genetic fluidity 

 that the group is in an evolutionary flux. 



The family is divided into five tribes (in the Engler 

 system of classification) each of which contains some 

 plants of economic significance, especially in the Tropics. 

 To the dweller in the temperate zones, however, only 

 one of these tribes, the Cucurbiteae, assumes real 

 importance. Here are gathered the gourds, pumpkins, 

 squashes, vegetable marrows, melons, cucumbers, water- 

 melons, etc., — a group of fruits and vegetables which 

 have pleased the palates of gourmets and intrigued the 

 interest of plant students and breeders for many a 

 generation. The vegetative parts of many species have 

 drastic purgative qualities, and the seeds of a large 

 number are rich in oils. Some species are useful orna- 

 mentals. The general characters of the family follow: 



Cucurbitaceae Juss. Gen. 393. 1789. 



Climbing herbs (rarely erect shrubsl generally equipped with 

 branched tendrils, now considered modified branchlets; leaves 

 alternate, palmately veined, entire or more or less divided; flowers 

 usually (but not always 1 unisexual and with both kinds ordinarily 

 on the same plant, regular, perigynous; corolla and calyx usually 

 with the members united; stamens regularly 5 or 3 (by adnation 

 of two pairs), rarely and irregularly 4; anthers sometimes straight 

 but often curved or variously contorted; ovary usually 3- or 

 5-carpelled, sometimes irregularly 4 or 6, inferior; fruit a pepo 

 i.e., with a thick rind and a fleshy or spongy many-seeded center , 

 rarely dehiscent. 



About 90 genera and 700 species, mostly of the warmer parts 

 of the world. 



KEY TO TRIBES. -After Muller and Pax) 



Anthers more or less distinct. 



Stamens with filaments free or with some pairs united. 



Filaments 5 (rarely 4) entirely free or united at the base. 



/. Fevilleae. 

 Filaments 3 rarely 2 or 4 ' by adnation of two pairs. 



Pollen sacs straight or somewhat curved. //. Melothrieae. 



Pollen sacs S or U shaped ///. Cucurbiteae. 



Stamens with filaments united in a tube IV. Sicyoideae. 



Anthers united in a ring V. Cyclant hereae . 



The Fevilleae, Tribe I, is of interest only as a 

 source of certain drugs and a few ornamentals. 



The Melothrieae, Tribe II, contains among others 

 three genera of some importance: Melothria, with a 

 number of ornamental species, the small fruits of which 

 are of minor value as food in the Tropics ; Cucumeropsis, 

 one species of which, C. edulis from tropical Africa, 

 bears edible fruits a foot long and three inches thick; 

 Telfairea, an African genus of two species, both of which 

 produce oily edible seeds; and Kedrostis, an East Indian 

 species which is said to have edible fruits. 



The Cucurbiteae, Tribe III, contains the Naras, 

 Acanthosicyos horrida, a leafless thorny erect shrub 

 with edible seed and fruits which are about 5 inches in 

 diameter and of a delicious subacid flavor; Hodgsonia 

 heteroclita of Burma and the Himalayas also with 

 edible seeds; and the more important gourds, squashes, 

 etc., described in detail in the following pages. 



The Sicyoideae, Tribe IV, is notable for the 

 Chayote — the fruit of Sechium edule — a favorite 

 vegetable in Central America, the culture of which 

 has spread through the warmer parts of America and 

 into the Mediterranean region in Europe. A related 

 plant, the Tacaco, Polakowskia tacaco, from northern 

 South America, has also somewhat similar edible fruits. 

 Coccinea, a genus of about 14 species from Southern 

 Asia and Africa, has several species of ornamental value; 

 and the fruits of C. cordifolia (C. indica) are used in 

 curries in India, while those of some, at least, of the 

 African species are used to some extent as food. 



The Cyclant hereae, Tribe V, contains a single genus 

 of 30 or more species, of which, a variety of one, Cyclan- 

 thera pedata var. edulis, is cultivated in Peru and 

 Bolivia for its large edible fruits. 



KEY TO IMPORTANT GENERA OF THE TRIBE 

 CUCURBITEAE 



Lobes of corolla fimbriate 1. Trichosanthes 



Lobes of corolla not fimbriate; 

 Corolla rotate; 



Calyx tube of staminate flowers much lengthened. .2. Lagenaria 

 Calyx tube of staminate flowers short; 



Stamens attached to throat of calyx 3. Momordica 



Stamens inserted in calyx tube; 



Flowers in racemes 4. Luff a 



Flowers solitary or fasciculate; 



Calyx lobes somewhat leafy, serrate, recurved. 



5. Benincasa 

 Calyx lobes subulate, entire; 



Tendrils 2-3 fid, connective short 6. Citrullus 



' Comparatively recent papers which should be consulted are: The series of articles on Cucurbits by various authors in the "Bulletin 

 of Applied Botany, of Genetics and Plant-breeding," volume 23, No. 3. pp. 1-560. Leningrad 1930; and also the paper on the " Cultivated 

 Plants of Mexico, Guatemala, and Colombia " by Bukasov et al. especially chapter 19 on the Cucurbitaceae i Supplement 47, to the same 

 journal, 1930. 



The Russian agriculturists writing in the publications mentioned have used a system of classification and a series of Latin names (mostly 

 for the purpose of designating geographic races or other groups within the various species which are, for the purposes of this account, too 

 involved to warrant inclusion and explanation, although their study is bringing out facts which must be considered in a monographic study 

 of the Cucurbits. 



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