Phaseolus vulgaris
Green beans are crisp, tender pods, including green and yellow wax types. They are an easy Northeast garden crop and a familiar summer preserve.1
Green snap beans, wax beans, pole beans, shell beans, and dry beans are all forms of the same species, Phaseolus vulgaris; the difference is largely the stage and part harvested.2
The string in older “string beans” is a tough fiber running along the pod seam. Modern stringless cultivars were selected to reduce it. A snap bean is harvested before the seeds and pod wall fully mature; leave the same kind of plant longer and the pod eventually becomes papery around dry beans.2
Round, slender pods and broad, flat pods are the two general forms; flat varieties tend to have a more intense flavor. Cooked green-bean aroma is unusually complex, combining sulfurous and freshly green compounds with mushroom-like octenol and floral linalool. Once harvested, the pods respire rapidly, consume their sugars, lose moisture, and become less sweet and crisp even in cold storage.3
Footnotes
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University of Maine Cooperative Extension, “Food & Nutrition for the Home Gardener,” accessed July 17, 2026. ↩
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University of Maine Cooperative Extension, “Vegetable Varieties for Maine Gardens,” accessed July 17, 2026. ↩ ↩2
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Harold McGee, On Food and Cooking: The Science and Lore of the Kitchen, rev. ed. (Scribner, 2004), PDF p. 350. ↩