{"id":2521,"date":"2025-08-20T09:00:57","date_gmt":"2025-08-20T09:00:57","guid":{"rendered":"https:\/\/agrilife.org\/westtexasrangelands\/?p=2521"},"modified":"2025-08-19T15:01:05","modified_gmt":"2025-08-19T15:01:05","slug":"dr-landers-rare-discovery-in-the-roots-of-twin-leaf-senna","status":"publish","type":"post","link":"https:\/\/agrilife.org\/westtexasrangelands\/dr-landers-rare-discovery-in-the-roots-of-twin-leaf-senna\/","title":{"rendered":"Dr. Lander\u2019s Rare Discovery in the Roots of Twin-leaf Senna"},"content":{"rendered":"

\"\"<\/a>It was a spring day in Schleicher County around 1985. Dr. Landers was waiting on students to finish a range contest when he decided to do a local rancher a small favor. Twin-leaf senna (<\/span>Senna roemeriana<\/span><\/i>) is a toxic plant known for causing livestock poisoning, and he had spotted a patch nearby. On a whim, he dug up about a dozen plants.<\/span><\/p>\n

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Curiosity got the better of him, and he cut into some of the swollen main roots. To his surprise, inside were insects in various stages of growth\u2014from grub to adult. He sent them to Texas A&M for identification and learned that they were an extremely rare species, with the last documented collection dating back to 1923.<\/span><\/p>\n

Could this insect have been a natural control for twin-leaf senna? He wondered about it, but, admittedly, he never followed up on the discovery.<\/span><\/p>\n

Twenty Years Later\u2026<\/b><\/p>\n

Two decades later, he returned to dig up another dozen plants\u2014this time on shallow soil where there was a plant every meter or so. He found no swollen roots, no insects, and the ranch had no history of twin-leaf senna poisoning.<\/span><\/p>\n

Over his career, he had seen most cases of poisoning occur with young kid goats just beginning to graze. There was only one instance involving a cow, and that was on severely depleted rangeland in Sutton County. His observation is that kids learn what to graze by watching their mothers\u2014if mom avoids twin-leaf senna, the kids usually do too.<\/span><\/p>\n

The Real Solution: Management, Not Chemicals<\/b><\/p>\n

In his experience, twin-leaf senna problems are almost always a management issue rather than something you solve with herbicide. Here\u2019s Dr. Landers\u2019 advice:<\/span><\/p>\n