Isoetes Lechleri Mett.

Abstract

During July, 1928, I received from Dr. W. R. Maxon, at the U. S. National Museum, a large number of specimens representing a gather-ing of Isoetes made in Colombia. These were collected by Messrs. E. P. Killip and Albert C. Smith (No. 17964.) during the exploration in Colombia under the auspices of New York Botanical Garden, Gray Herbarium, U. S. National Museum, and Arnold Arboretum. The date of collection is Jan. 21, 1927, and the Eastern Cordillera locality is Dept. Santander; Laguna de Cunta, edge of Paramo de Santurban, alt. 3880 meters. Environment: Rooting in mud in shallow water at margin. Usually submerged but often aquatic and even entirely terrestrial. All the plants are rather small, but many of them bear sporangia packed with mature spores. A careful examination of these specimens revealed features approximating those of the Peruvian species I. Lechleri Mett. as described by A. Braun (Verh. des Bot. Verein fur Brandenburg. 4. 1862.) It is to be noted in this connection, that Braun's I. socia and I. Karstenii, the latter from Venezuela (loc. cit.), were, apparently with Braun's concurrence, united with I. Lechleri by Motelay and Vendryes (Actes Soc. Linn. Bordeaux. 36. 1883.) These forms are alike in showing smooth megaspores and complete velum. The other Peruvian species, I. triquetra A. Br. is without velum and has tuberculate megaspores. It seems almost impossible to obtain any authentic material of these South American forms. Mr. E. P.