Bad at Goodbyes

Rough Transcript

Intro 00:05

Welcome to Bad at Goodbyes.

On today’s show we consider the Cork Palm.

Species Information 02:05

The Cork Palm is a critically endangered tree native to the island of Cuba in the Caribbean Sea. Its scientific name is Microcycas Calocoma and it was first described in 1868.

Description

The Cork Palm is an arborescent cycad; Arborescent means tree-like, its a term to loosely describe the visual growth form of a plant. And Cycads are an absolutely ancient class of plants. We have fossil evidence of cycads from the Early Permian period, roughly 280 million years ago. So this is the time of supercontinent Pangea, predating the dinosaurus. There were Cycads before there were dinosaurs. And in fact, you and I are closer in time to say T Rex and Triceratops, than those dinosaurs are to the earliest cycads, by about 100 million years.

 

So the cycads have this long long lineage, 100s of millions of years of successful reproduction and slow evolution. And are still relatively abundant globally. Some cycad species are very common houseplants.

 

But our Cork Palm, our subject today, is not common. And, it is not a palm. Cycads and palms, though they appear to share cursory physical attributes and similar adaptations, are totally unrelated. This is a case of what is called convergent evolution. Convergent evolution is when species evolve similar features or behaviours but do not share a genetic lineage; they’ve independently evolved similar traits rather than inheriting them from a common ancestor. Like how birds, bats, and insects all evolved wings for flight. Or how Cacti (native to the Americas) and Euphorbias (native to Africa) both independently evolved sharp spines. So too with cycads and palms who often both have feathery frond-like leaves and a single cylindrical, unbranched trunk. This is convergent evolution. Habitat pressure leading to similar adaptations, but in distinct genetic lineages. 

 

And so our Cork Palm, though it is not a palm, does kind of look like one. It is a small tree that can reach roughly 30 feet in height, with a thick straight trunk that can grow up to 2 ft in diameter. It generally does not branch, and the frond-like leaves emerge from the top of the trunk, creating a crown of foliage. As new leaves develop, they push the older leaves downward. As older leaves wither and fall off, their leaf base persists; this is the tissue that connects the leaves to the trunk; they remain attached, helping protect the trunk from damage and water loss, and give the Cork Palm a textured appearance.

 

The leaves themselves are green and frond-like, divided into long drooping leathery leaflets that are long and narrow and taper to a pointed tip. The Cork Palm’s leaflets can grow to a foot long but are less than an inch wide, with an entire margin, meaning the leaf edges are smooth.

Reproduction

The Cork Palm is cone-bearing, and dioecious, meaning individual plants are either male or female. Male individuals produce pollen cones, female individuals produce seed cones. Male cones are yellowish-brown and covered in fine hairs and are quite large, growing up to a foot and half in length. Female cones are even larger and more oval-shaped than male cones; they can reach lengths of up to 3 feet with diameters of 5 to 6 inches. They are also yellowish-brown but have a more velvety texture.

 

The initial cone growth begins in May and it takes about 4 months for the cones to fully develop, with pollination occurring in September/October.

 

Biologists have found evidence that suggest the Cork Palm is primarily pollinated by a small beetle species, which feeds on pollen and also mates within the protective cone.

 

Once pollination occurs, the seeds within the female cones begin to develop. The seeds of the Cork Palm are relatively large, typically around one and a half inches long and one inch in diameter. They have a fleshy outer layer called the sarcotesta, which is initially green but turns reddish-pink as the seeds mature. The sarcotesta is kind of protective layer around the developing seed aiding in Water Retention and Nutrient Storage. Imagine a pomegranate seed, the soft red tasty bit is the sarcotesta.

 

In my research I could not find observation of how these seeds are dispersed. Though we can make some confident hypothesis. The nutrient-rich and bright red sarcotesta likely attract birds who would feed on the fleshy bits and then distribute the seeds in their excrement.

 

Also Cork Palm are often found in clusters, with many trees in a stand sharing some lineage. This suggests the seeds are distributed by gravity. Mature seeds released from the cones simply fall to the ground, not far from their parent plant.

 

So Cork Palm seed dispersal is by zoochory (that’s by animals) and barochory (that’s by gravity).

 

The Cork Palm is slow growing and slow to mature. After germination seedlings will take 17 or more years to produce their first cones. The Cork Palm is believed to live up to several hundred years old.

In The Dream

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In the dream,

 

One million generations, to seed and grow and cone and seed, and grow and cone and seed, the long flickering flame of life everlit across impossible timescales, through unfathomable change. A kind of hope, tucked into sweet sarcotesta, an enduring promise, a persistent standing guard over shifting lands, a living remembrance of forevers. To seed and grow and cone and seed, still today and, let’s hope, for innumerable tomorrows.

 

In the dream.

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Habitat

The Cork Palm is native to western Cuba, to roughly 6 populations within the province of Pinar del Río. This is a bioregion of tropical forests in a landscape formed by erosion, creating caves, sinkholes, and underground streams. These are rugged steep slopes, limestone hills, with patches of forest, and areas of exposed rock and scrub vegetation. This is a verdant, yet rocky, terrain, where pockets of plant life cling to the rocky hillsides.

 

The climate is tropical, with distinct wet and dry seasons. Summer temperatures can crest 100°F, winter temps rarely fall below 60°F. The region receives an average annual rainfall of roughly 40 inches, with the majority of precipitation occurring during the wet season from May to October. It is a substantial swing, with, for example, June seeing 10+ days of rain, and December only 1.

 

The Cork Palm shares its tropical home with:

Cuban Green Anole, Summer Tanager, Tropical Palm, Cuban Solitaire, Pitch Apple, Cuban Solenodon, Sickle Bush, Cuban Tree Frog, Madre de Cacao, Cuban Trogon, Cuban Crocodile, Mountain Palm, Singapore White, Cuban Bullfinch, Macho Palm, Blue Mahoe, Butterfly Pea, White Ginger, and many many more.

Threats

The primary cause of the historic population decrease of the Cork Palm is anthropogenic, human-caused, habitat destruction and fragmentation.

 

I think we likely have an idea of what habitat destruction means, but I realize that we use the term habitat fragmentation on the show regularly and have never really unpacked it. So, imagine a tree species that relies on the wind for seed dispersal. Fertilized seeds are blown away from the parent plant and ideally find purchase in viable soil, to germinate and spout. Now imagine a four lane highway is built near our tree. On one side of the highway is our tree, and on the other side is viable habitat. But, the wind dispersed seeds can no loner reach that soil, they fall fallow on the concrete. The tree’s habitat has not been wholly destroyed but it is now fragmented.

 

Or imagine a bird species that lives in a ring of forest around a field. And say they attract mates with their call. Then we build a factory in the field between the forests. We are thoughtful about it, we do not knock down a single tree and we build a low structure, knowing this is an avian flight path. And yet, the noise from the factory machinery prevents the birds from hearing one another’s mating calls. And so even though we haven’t directly destroyed habitat nor created a true physical barrier, we have fragmented that habitat, and imperiled the bird’s reproduction.

 

In the case of our Cork Palm, agricultural clearing and the construction of road and highway systems are the source of the cycad’s habitat fragmentation.

 

Today, reduced habitat, particularly for tobacco growing, and the poaching of individuals from the wild are the plant’s primary threats.

Conservation

Fortunately, the Cork Palm is legally protected, locally by the provincial and federal Cuban government and also internationally. The majority of its population is found in protected wilderness within the Vinales National Park.

 

And yet, a continuing threat to the Cork Palm is poaching of wild individuals, from public land, for illegal sale on the black market. The Cork Palm is highly sought after as an ornamental tree in exotic gardens for both its beauty and it rarely. And so about 15 years ago, horticulturists at the Montgomery Botanical Center (Miami, FL), responding to this threat, initiated an intensive cultivation and seed distribution program for the Cork Palm. They essentially flooded the market with viable seeds. That increased supply led directly to a steady decline in the price per seed, reducing the perceived rarity of the species and disincentivizing illegal wild collection.

 

There are robust offsite cultivation efforts occurring at botanical gardens globally and in Cuba. And onsite, within the species habitat, Cuban researchers continue to conduct fieldwork to locate previously undocumented populations and monitor their status.

 

Nevertheless the Cork Palm has been considered critically endangered on the IUCN Red List since 2003 and their population is currently in decline. Our most recent counts estimate that less than 250 Cork Palm remain in the wild.

Citations 23:01

Information for today’s show about the Cork Palm was compiled from:

 

Ania Pinares, Jorge González-Astorga, Andrew P. Vovides, Julio Lazcano, Wagner A. Vendrame,

Genetic diversity of the endangered endemic Microcycas calocoma (Miq.) A. DC (Zamiaceae, Cycadales): Implications for conservation. Biochemical Systematics and Ecology, Volume 37, Issue 4, 2009, Pages 385-394. – https://doi.org/10.1016/j.bse.2009.07.006

 

Botanical Gazette v.44 no.2, 118-141. (1907). “Microcycas Calocoma”. Otis W. Caldwell. – https://doi.org/10.1086/329295 

 

Botanical Gazette v. 47 no.2, 139-147. (1909). “Vascular Anatomy of the Seedling of Microcycas calocoma”. Helen Angela Dorety. – https://doi.org/10.1086/329818 

 

Botanical Journal of the Linnean Society, Volume 125, Issue 3, November 1997, Pages 201–210. “Pollination of endangered Cuban cycad Microcycas calocoma (Miq.) A.DC,”. Andrew P. Vovides, Nisao Ogata, Victoria Sosa, Esperanza Peña-García.  – https://doi.org/10.1111/j.1095-8339.1997.tb02254.x 

 

Bösenberg, J.D. 2022. Microcycas calocoma (errata version published in 2023). The IUCN Red List of Threatened Species 2022: e.T42107A243384251. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T42107A243384251.en

 

Cycad Newsletter Vol. 14, No. 2 (November 1991) “Microcycas calocoma: Portrait of a Species”. Garrie Landry. – https://cycad.org/content/newsletter/ 

 

Horttechnology. v. 21. 474-481. “Palma Corcho: A Case Study in Botanic Garden Conservation Horticulture and Economics. “ Kay, Judy & Strader, Arantza & Murphy, Vickie & Nghiem-Phu, Lan & Calonje, Michael & Griffith, M.. (2011). – http://dx.doi.org/10.21273/HORTTECH.21.4.474

 

Insecta Mundi. v. 70. “A new species of Pharaxonotha (Coleoptera: Erotylidae), probable pollinator of the endangered Cuban cycad, Microcycas calocoma (Zamiaceae)”. Chavez, Ramiro and Genaro, Julio A. (2005). – https://digitalcommons.unl.edu/insectamundi/70 

 

Wikipedia – https://en.wikipedia.org/wiki/Microcycas 

Music 24:23

Pledge 32:42

I honor the lifeforce of the Cork Palm. I will commit its name to my record. I am grateful to have shared time on our planet with this being. I lament the ways in which I and my species have harmed and diminished this species. I grieve.

 

And so, in the name of the Cork Palm I pledge to reduce my consumption. And my carbon footprint. And curb my wastefulness. I pledge to acknowledge and attempt to address the costs of my actions and inactions. And I pledge to resist the harm of plant and animal kin and their habitat, by individuals, corporations, and governments.

 

I forever pledge my song to the witness and memory of all life, to a broad celebration of biodiversity, and to the total liberation of all beings.