Revisiting the taxonomy of Helictotrichon schmidii (Poaceae, Poeae, Aveninae) from India, with updated regional distribution and conservation status

The taxonomy of Helictotrichon schmidii is discussed, a lectotype and a detailed description are provided, and its distribution in the Western Himalaya, India is expanded by new data. Detailed micromorphological study revealed that the species is closely allied to the genus Tzveleviochloa by having the lemma tip entire to slightly cleft and 2-aristate like Trisetum, lodicule asymmetrically lobed and ovary densely hirsute at the apex. Thus, a new combination in the genus Tzveleviochloa is proposed, and its circumscription, especially lemma, ovary and lodicules, and taxonomy is clarified. In addition, comparison is made among the three closely related oat-like perennial grasses, Helictotrichon s. str., Trisetopsis and Tzveleviochloa.