Impossible to answer that - the number of blooms per stalk isn't the issue, its a bit easier to tell what they might conceivably be if one knows the height of the plants, the colour range, and whether they're fragrant or not. There are many varieties of Lathyrus.

Exhibition Lathyrus Odoratus. Boltons were one of the best sweet pea growers. We grew stems with as many as eight spencers with 9 and 10 sometimes. The seeds were sown in October in a cold frame, planted out in March.

unless its one of the perenial peas, they have a lot of flowers per stalk. any chance of a photo?