Cucurbita foetidissima

Cucurbita foetidissima, has numerous common names, including: buffalo gourd, calabazilla, chilicote, coyote gourd, fetid gourd, fetid wild pumpkin, Missouri gourd, prairie gourd, stinking gourd, wild gourd, and wild pumpkin. The plant is tuberous and a true xerophytic plant found in the Southwestern United States and Northwestern Mexico. The type specimen was collected from Mexico by Humboldt and Bonpland sometime before 1817.

The feral perennial Buffalo gourd has evolved in the semiarid regions and is well adapted to desert environments. It has abundant yields of oil, protein and carbohydrates. The carbohydrates that are formed in the tap root have led to the idea to grow the plant for biofuel.
The fruit is consumed by humans and animals. When the fruit is mature, a stage marked by increasing desiccation of vine, leaves, fruit-stem, and fruit itself, it begins its final gourd stage.
Geographic location and genetics make it highly likely that Cucurbita scabridifolia is a naturally occurring hybrid of C. foetidissima and Cucurbita pedatifolia.

Cucurbita foetidissima requires little water and grows most rapidly in semiarid and arid environments. Warm weather is required during the vegetation period which is 5 to 8 months. This perennial is well adapted to marginal agricultural lands like sandy loam soils which have to be well drained. Germination temperature range is between 15 °C and 37 °C with an optimum at 25 °C.
The maximum depth for a successful germination is 12 cm. The germination is possible in a pH range from 2.2 (germination rate 15% ) up to pH 8 (germination rate 90%). Asexual propagation is possible from nodal roots.
The leaves of the buffalo gourd are typically entire and heart shaped with a 10–13 cm base and 20–25 cm length. 

The flowers are borne singly at the nodes of the vines after a given amount of annual vegetative growth has taken place.
The fruit has a diameter of 7–10 cm, the fruit weight is 120 g to 150 g and number of seed per fruit of 292 to 315.The seeds weigh about 4 g per 100 seeds and the seeds are 12 mm long and 7 mm wide. The seed coat accounts for about 30% of the seed weight. The seeds often remain viable for months or even years within an undamaged gourd. One hectare of can produce 2.5 tons of seed.
A fleshy tap root is formed by the plant which is used as a storage and overwintering structure. The central tap root can weight up to 72 kg. A four-year-old root grown under cultivation can reach a fresh weight of 45 kg and a length of 2.5 meters.

(Full size image: https://upload.wikimedia.org/wikipedia/commons/9/92/Cucurbita_foetidissima_fruit%2C_leaves%2C_and_vine.JPG )
Distribution

Cucurbita foetidissima is native to North America in the U.S. (Arizona; Arkansas; southern California; Colorado; Kansas; Missouri; southern Nebraska; Southern Nevada, New Mexico; Oklahoma; Texas; and southern Utah) and Mexico (Aguascalientes; Chihuahua; Coahuila; Guanajuato; Guerrero; Hidalgo; northern Jalisco; Mexico; Nuevo León; Querétaro; San Luis Potosí; Sonora; Tamaulipas; and Zacatecas)

Ripe fruit:
(http://upload.wikimedia.org/wikipedia/commons/0/0b/Cucurbita_foetidissima_fruit_2003-02-04.jpg)


Ripe fruit on a hand
https://upload.wikimedia.org/wikipedia/commons/3/34/Cucurbita_foetidissima_fruit_Rest_of_the_plant_looked_long_dead.jpeg