Yeah, a cucumber. I’ve never thought of the cucumber as particularly cool. Crisp and juicy? Yes. Cool? Well . . .. Before I start rambling on about the hipness of this vegetable, I should admit that its coolness refers not to trendiness but to temperature — quite simply, a cucumber feels cool to the touch. Yet, this member of the gourd family offers far more than catch phrases and temperature gauges. Available year-round, it’s a staple ingredient in many dishes and a star in its own right. Rumored to have originated in South India, the cucumber has been cultivated for at least 4,000 years. In spite of its longstanding popularity, it didn’t arrive in North America until the late 15th century. Christopher Columbus introduced the first cucumber to Haiti in 1494. From there demand for this crunchy, green vegetable spread. And just what do people do with all these cucumbers? A third of the roughly 100 varieties grown are used for pickling. The rest we eat in salads, from crudite platters, in dips, and as …