Image of Exploding Cucumber

Description:

Slo.: navadni trkavec - Habitat: ruderal, stony ground of an abandoned backyard, calcareous ground, flat terrain, full sun, dry place, exposed to direct rain; average precipitations ~ 1.200 mm/year, average temperature 16 deg C, elevation 50 m (160 feet), Mediterranean phytogeographical region. - Substratum: red soil, stony, skeletal ground. - Comment: Encounter with Ecballium elaterium is an exciting experience for kids. It is such a fun to help the plant in distribution of its seeds! Truly, its technique of distribution of seeds is very special. Fruits in the form of small, up to 5 cm long, spiky 'cucumbers' form high internal hydrostatic pressure at the time of their ripeness. When in such condition, the slightest touch of the plant triggers a violent 'explosion' (or usually several of them in larger stands). The fruit abruptly detaches from its peduncle and propels through the hole where it was attached a high speed jet of fluid with seeds in one direction. The fruits themselves (still containing some seeds) fly away like jet propulsion projectile in the opposite direction. The act is surprisingly violent. If one strongly squeezes a ripe 'cucumber' with his fingers the seeds may squirt several meters away. However, doing this is not only fun but comprises also some dangers. The fluid may cause strong skin reaction with some people and represents a real threat for eyes. In addition it is extremely bitter. Definitely kids should not 'play wars' using these fruits as guns. - The plants are dioecious, that means there are two types of them. The male plants bear only male flowers, which have only stamina and the female plants have only female flowers, which have only pistils and bear fruits. The pictures show female plants. Ecballium elaterium is a typical Mediterranean plant growing in all countries surrounding the Mediterranean Sea. It loves dry ruderal places, roadsides and stony disturbed areas. Often it covers quite extensive expanses. In Slovenia it can be found only in its extreme southwest corner on the Adriatic Sea shore. - Ref.: (1) I. Schnfelder, P. Schnfelder, Kosmos Atlas Mittelmer- und Kanaren Flora, Franckh-KosmosVerlags GmbH& Co. (2002), p 130. (2) A. Martini et all., Mala Flora Slovenije, Tehnina Zaloba Slovenije (2007) (in Slovene), p 469. (3) M.A. Fischer, W. Adler, K. Oswald, Exkursionsflora sterreich Liechtenstein, Sdtirol, LO Landesmuseen, Linz, Austria (2005), p 463.