I Yam Not a Tortoise but a Plant

The caudex of the Dioscorea mexicana.

Dioscorea mexicana, commonly called Mexican Yam or Tortoise Plant, is native to Mexico, El Salvador, and Panama.  Dioscorea is made up of around 600 species in the Dioscoreaceae family and has a world-wide distribution range.  Originally in the Testudinaria genus and named after ‘Testudo,’ a genus of tortoise, it was later grouped into the genus Dioscorea.

The plant’s caudex (or modified stem) resembles the shell of a tortoise.  The caudex itself is a partially exposed tuber that is covered in grayish-brown scales.  It is divided into polygonal plates that are scored by deep furrows.  This species typically goes dormant during the winter, though this year even without water for nearly four months the stem didn’t die back and still looks great, so we shall see what the future holds.  From what I have experienced, heard from other growers, and also read, this plant sometimes either doesn’t die back during the winter or sends out a new stem earlier or later than expected, so watch the plant and not necessarily the calendar.  The new stem can grow 15 to 20 feet in one season!

Dioscorea mexicana’s flowers bloom in late summer.

Dioscorea mexicana is dioecious meaning that the individual plants in the species are either male or female.   The leaves are glossy green and heart-shaped.  Flowers are greenish with dark purple centers and bloom in late summer.  Although considered inconspicuous, I feel the male flowers add some visual interest.  The caudex requires shade, usually provided by surrounding vegetation, while the vining portion of the plant needs full sun.  It prefers to grow in a well-drained soil.  Dioscorea mexicana is mostly propagated by seed, but although stubborn can be grown from cuttings.

If you can find one, this plant will have even the best plant enthusiasts talking and asking questions.  Its easy winter care regimen (in most years) makes it a great choice for an exotic tropical look.  During winter months greatly reduce the amount of water given to the plant; a light monthly watering is needed at most.  I couldn’t find much information about and personally don’t know its hardiness but wouldn’t expose it to temps much below freezing for extended periods of time.  Slowly bring it out of dormancy in the spring and give it lots of water during the hot growing summer season.   Despite being nicknamed after a slow mover, Dioscorea mexicana quickly proves itself a crowd pleaser!

-Matt Fleming, Horticulturist

Smithsonian Gardens presenta Las Orquídeas de Latinoamérica

Oncidium Red Stars ‘Rooster’

La Institución de Smithsonian tiene una larga historia de la recolección de plantas para compartir su belleza con el mundo. ‘Smithsonian Gardens’  sigue compartiendo esta tradición a través de su colección de orquídeas. Esta colección ha aumentado desde 1974 cuando adquirieron las primeras cinco plantas. Desde entonces, la colección de orquídeas ha florecido enormemente y hoy  tenemos a más de 8,000 especies en nuestro invernadero.

Las plantas que forman esta colección son utilizadas para elevar la belleza y la maravilla de los museos Smithsonian. Cada año podemos disfrutar la gran variedad de sus brillantes colores y formas cuando muestran sus encantadoras flores. Aprovechen y celebren estas maravillosas plantas cuando visiten a los museos Smithsonian. Podrán ver orquídeas que representan a países tan lejanos como China o más cercanos como nuestros vecinos de México.  La exposición este año celebran Las Orquídeas de Latinoamérica. Visiten y admiren las bellas flores exóticas que tenemos en exhibición en el Museo Nacional de Historia Natural y reciban más información y detalles que les ofrecemos en español e inglés.

– Sarah Mirabal, Orchid Intern

2013 Orchids of Latin America Exhibition

Coryanthes vasquezii orchid

At Orchids of Latin America, the 2013 annual Orchid Exhibition, you can explore the rich crossroads where orchid botany, horticulture, and Latin American cultures meet. Learn about the importance of orchids in Latin American folklore and cultural traditions, see how the region is a hotbed for scientific research on orchid biology and evolution, and discover conservation efforts to preserve orchids and their habitats for future generations. And, of course, enjoy the beautiful orchids from the Smithsonian Gardens and the U.S. Botanic Garden Orchid Collections.

On Saturday, February 23, 2013, join us for ¡Fiesta de las Or-KID-ias! a free family festival celebrating Orchids of Latin America.   At the fiesta, you can help make a beautiful orchid mosaic and paper orchid garlands, pot your own orchid to take home, and talk with experts about a display of unique plants from our collection.  Other fun activities include face painting and temporary tattoos!

Orchids of Latin America is hosted by Smithsonian Gardens, the National Museum of Natural History, and the United States Botanic Garden with support from the Smithsonian Latino Center.  The exhibit will run from January 26th through April 21st at the National Museum of Natural History.

-Sarah Watling, Education Intern