Dennis Szeszko to Speak at September 7 Meeting

Dennis will cover the Barkeria genus.

Our speaker at the Thursday, September 7, meeting is Dennis Szeszko who will cover the genus Barkeria.

Dennis Szeszko had what many readers would consider a “dream job.” He was employed by the Mexican government as a botanist and was lucky enough to spend five years doing field research looking for orchids in the wild. As part of his research objectives, Dennis completed a flora of all the orchid species that grow in Mexico State, which became the basis for his book, La Orquideoflora Mexiquense. The book was published in 2011 by the Mexican government as a large-format “coffee table” book to commemorate both the bicentennial of Mexico’s independence from Spain and the centennial of the Mexican Revolution.

The title of Dennis’s presentation at our meeting is “A Barkeria Odyssey.”

Subscribers to the AOS magazine, Orchids, may remember a series of recently published articles in the November 2021, February 2022, and June 2022 issues regarding Barkeria orchids. Dennis, in conjunction with Robert Marsh, coauthored the series, which synthesized the current knowledge space about the genus. He aims to distill those three lengthy articles into a succinct 60-minute presentation.

The first 20 minutes of the talk will provide an overview of the 17 known species of Barkeria, explain some taxonomy, and show many of the species in their natural habitat. Dennis will talk about why the authors proposed splitting the genus into three different sections and what that means for amateur growers attempting to cultivate the species ex-situ. The cleaving of the genus into three groups is the main takeaway from the discussion, because it allows growers to understand the reasons why they failed in their attempts to grow the wrong species for their climate in the past and also gives pointers as to which species would be easiest to attempt in the future. More generally, Dennis will discuss the biogeography of Mexican orchids and give information about seasonal rainfall, forest types, and elevation, which should prove useful for anyone attempting to grow other genera of Mexican orchids.

The second 15 minutes of his talk will discuss efforts at hybridizing within the genus. Recent breeding efforts using the Obovata section have focused mostly on expanding the palette of colors and patterns while crosses with species in the Scandens section have increased the flower size and fertility of the hybrids. He will present many pictures of the most recent crosses with a brief explanation of how and why the parents were chosen in anticipation of the sought-after results.

The final 10 minutes of Dennis’s presentation will provide growing tips (do’s and don’ts) concerning ex-situ cultivation of species and hybrids. It will be tailored for growers in the Houston area or Gulf Coast states. He will discuss which species are the easiest to grow and the reasons why, along with cultivation tricks.

There will be time allotted at the end for discussion and questions. Priority will be given to questions about Barkeria, but questions pertaining to other Mexican genera or species may also be raised, time permitting.

Barkeria plants will be available for sale.

Please join us in person or virtually for Dennis’s presentation. The meeting begins at 7:30pm at First Christian Church, 1601 Sunset Boulevard in Houston.

Cover of November 2021 Orchids magazine, published by the American Orchid Society, showing Barkeria Oaxacan Showers ‘Sunshine’ (Rebecca Marsh x Obosa Ivory). Dennis Szeszko and Robert Marsh coauthored “Barkeria Hybrids—Part 1: Obovata section,” pp. 842–8. Photo by Robert Marsh.