Pennyroyal Mint Seeds. 90 Days. Heirloom, Open Pollianted, Non-GMO. AKA: Penny Royal Mint. Pennyroyal is a flowering herb perennial member of the mint family often used ornamentally becuase of it's beautiful lavender flowers. While it has traditionally been used as a medicinal, herbal tea and culinary herb, Pennyroyal can be toxic if the dose becomes large enough, so use caution with ingesting Pennnyroyal. About 476,000 Seeds / Oz.