Those, my friends, are snap peas. The ones on the left are Sugar Magnolia snap peas; I don't know what the name of the ones on the right is, but they are either also Sugar Magnolia peas or a related variety bred by Alan Kapuler of Peace Seeds. Here's the description from his blog:
Pisum sativum Sugar Magnolia Purple Snap Vine Pea 25/5.00 Vigorous vines with purple flowers and purple 3-4” snap pods of fine flavor. This year’s seed stock has a mixture of tendril types: regular, hypertendril and vetch (no tendrils). Unexpectedly, the cross of a Parsley Bush Pea with a Purple Podded Snap Vine Pea generated a hypertendril trait. Hypertendrils are very distinctive, they hold a population of vine peas together, a useful self-supporting characteristic.
I did not get my seeds directly from Peace Seeds, but from a friend who generously passed some along to me. Mine appear to be the regular tendril variety. The peas I received also appear to be a mix of Alan Kapulers snap pea strains, but the true purple Sugar Magnolia are the most beautiful and also, I am happy to say, the best tasting and most tender. I will be selecting for the most purple podded plants to grow out next year.
They are not as good tasting as Amish Snap - nothing is - but they are very pleasant peas and the astonishing colour actually survives cooking! Pretty much unheard of, in purple podded beans and peas. As such, I intend to continue to grow them regularly to use as a garnish and point of colour in spring vegetable dishes, which otherwise tend towards the purely green. You can see them, cooked, in this dish of Peas & Cheese.
They are very attractive as plants, and the peas can get quite big before becoming too tough to eat. This is another bonus, as it means they have a range of several days that they will hold on the plant. One of the tedious parts of early summer is having to get out there and pick peas, Every. Single. Day. If not twice!
When Alan Kapuler says "vigorous vines" this is what he means. Even in this dry, hot year they have reached the top of our 7' trellis and are not done yet. Note too, that my assessment of their flavour and lasting qualities was made this year, and they are likely to do even better in a year that's kinder to peas. I took these photos during last week's heatwave, so they, like all the peas, stopped blooming and there are no flowers to be seen. However, they have very pretty flowers, in 2 tones of purple.
I'm afraid these will be very hard peas to find. I am aware of only one company in Canada that sold them this year, and that was Richter's, as part of their Seed Zoo. That's a brutally expensive way to get seed, but on the bright side peas are amongst the easiest of vegetables to grow out and save seed from. They describe theirs as the hypertendril strain.