The Genus Encyclia–Part 2, Caribbean species

Brrr!

(Start at The Genus Encyclia–Part 1)

We woke this morning to frigid temperatures and about 2″ of snow, so this seems a perfect day to think about the Caribbean* Encyclia species. Instead of focusing on winter’s cold, imagine Encyclia tampensis growing at the edge of a tropical hardwood hammock on Sugarloaf Key, Encyclia plicata in a sun-baked Bahamian coppice, or Encyclia phoenicea in the Cayman Islands, not far from the beach. As suggested by these localities, most of the Caribbean Encyclia species are warm- to hot-growing and many can be grown well alongside cacti and succulents.

These species can be difficult to find at orchid nurseries, but a handful turn up from time to time as oddballs. I suspect you will more likely find them at nurseries in Florida, rather than on the west coast. Here are a few that are commercially available and are well worth growing.

*The Bahamas and Florida are not, technically speaking, in the Caribbean, but with respect to Encyclia biogeography, the Greater Antilles, Bahamas, and Florida can probably be considered a single region.

Encyclia tampensis

Typical colored form of E. tampensis.

With a natural range encompassing southern Florida and the Bahamas, E. tampensis isn’t exactly a Caribbean species (but see above re: geography vs biogeography); however, it is definitely the most readily available of this group of orchids. Before it was legally protected, E. tampensis would have been easily obtained from the wild by commercial and hobbyist orchid growers in Florida. E. tampensis is a relatively small species with flowers that are cute, rather than beautiful. Both the normally colored form shown above and an alba form with white lip and green tepals are commercially available. The plants I have grown have a sweet honey-like fragrance during the day.

Encyclia phoenicea

E. phoenicea flowers

Possibly the finest of all the Caribbean species, Encyclia phoenicea from Cuba, the Cayman Islands, and Turks and Caicos has rigid, sword shaped leaves, glossy pseudobulbs, and beautiful purple flowers. It is most famous for its distinctly chocolate fragrance–I can confirm that the fragrance is fantastic! For obvious reasons, Cuban Encyclia species are often rare or absent from U.S. collections, but E. phoenicea was introduced to cultivation in the 1950s, before the revolution. More recently, offspring of plants originating in the Cayman Islands have also become available. Somewhere, and the source now escapes me, I heard that the early collections often had a folded lip, suggesting natural hybridization with E. plicata (see below), and the implication was that they were collected for their unusual appearance instead of more typical plants. Experiments in self-pollination reported by Ruben Sauleda and Pablo Esperon have indicated that Cuban E. phoenicea often carry genes from E. plicata and E. pyriformis, while those from the Cayman Islands are unhybridized [1].

A different clone of E. phoenicea illustrating some of the variability of the species, particularly in the lip.

Encyclia plicata

E. plicata flowers with the distinctive folded labellum

Encyclia plicata, from the Bahamas and Cuba, is clearly closely related to E. phoenicea. Its primary difference, from a horticultural point of view, is the folded lip, which gives the flowers the appearance of some strange bird of prey. The fragrance of this species is also distinct, at least among the plants I have grown. While E. phoenicea lived up to its common name of “chocolate orchid,” my E. plicata smelled exactly like root beer candy.

Encyclia rufa

E. rufa with unmarked yellow flowers and a rolled labellum

Encyclia rufa is also from the Bahamas. Its somewhat ungainly flowers are very strongly scented. I like the fragrance very much, but it is hard to describe beyond “fresh and floral”

Encyclia pyriformis

A small E. pyriformis plant growing on a slab of cork bark

Encyclia pyriformis is another Cuban species, though it is much smaller than E. phoenicea or E. plicata. The clone that I grew had a chocolate fragrance almost identical to that of E. phoenicea.

Encyclia moebusii

Richly colored flowers of E. moebusii

Encyclia moebusii is unusual for the rich purple color that covers the entire flower rather than being restricted to the lip as in many other Encyclia species. Native to Cuba, it was described in 1985 and entered cultivation more recently. The plant shown came from Hamlyn Orchids, the nursery owned by Caribbean orchid specialist Claude Hamilton in Jamaica. My nose cannot detect any fragrance from this species.

Encyclia bocourtii

The flowers of this E. bocourtii clone were widely spaced on a long inflorescence

Encyclia bocourtii, also from Cuba, was described in 2005. To my eye, the flowers (or at least their color scheme) are reminiscent of the Central American E. alata, but it is surely more closely related to the other Cuban species.

Reference

Sauleda, RP, and Esperon, P, (2018). Artificial Self-pollination (Autofecundation) as a Taxonomic Tool – Encyclia phoenicea (Lindl.) Neumann. New World Orchidaceae–Nomenclatural Notes 34: 1-14. http://www.newworldorchidaceae.com/

Further reading

Although it lacks the more recently descibed species and natural hybrids, Carl Withner’s book is probably the most comprehensive text on Caribbean Encyclia species:

Withner, CL (1996). The Cattleyas and their Relatives: Volume IV. The Bahamian and Caribbean Species. Timber Press, Portland, Oregon.

Ruben Sauleda’s New World Orchidaceae website is a compendium of his research papers on orchids, including many fascinating tidbits on Caribbean orchids.

Up Next: Mexican and Central American Encyclia species

The Genus Encyclia–Part 1, Introduction and general notes on cultivation

Encyclia cordigera var. rosea

Winter, and the subsequent slowdown in garden activity, has given me the opportunity to dig through old photos and think about a more detailed series of posts than I usually write. This series on the orchid genus Encyclia was adapted from a talk that I gave to the Triangle Orchid Society and other local North Carolina orchid societies. I’m currently planning to break it into five or six parts, to be posted over the next few weeks. Apart from this introduction, I will focus on specific plants from three main regions of Encyclia biodiversity and then conclude with a post on Encyclia hybrids.

Introduction

Encyclia is a genus of neotropical orchids whose natural range extends from Florida to Argentina. There seem to be three main regions of Encyclia biodiversity: the Caribbean islands, Mexico and Central America, and the Brazilian shield south of the Amazon basin. Encyclias are characterized by heteroblastic pseudobulbs (see below) which are often tightly clustered, 1-3 strap-like leaves which may be leathery or rigid, and flowers with the lip not fused to the column (unlike Epidendrum, in which Encyclia species were previously classified).

Large pseudobulbs and leathery leaves of Encyclia hanburyi

Encyclia flowers are generally borne on long, upright inflorescences which are sometimes branched. They are usually pollinated by bees and are often strongly fragrant with colors in various shades of white, purple, and yellow. Apart from the flowers, the pseudobulbs of Encyclia plants are probably their best feature. Heteroblastic simply means that the pseudobulb is formed from two or more stem segments of unequal size, and since Encyclias often grow under quite harsh conditions, the water-storing pseudobulbs are often large (up to the size of a large hen’s egg) and glossy. A well-grown Encyclia plant in flower gives an impression of both toughness and elegance.

The almost spherical pseudobulbs of Encyclia gallopavina. When grown under bright light, many Encyclias become suffised with red or brown pigment.

General cultivation notes

The following constitutes instructions for successfully growing most Encyclia species. When considering specific species in later posts, I’ll make note when a plant’s growing requirements differ from these instructions.

Encyclia tampensis growing on a tree branch in Everglades National Park

Encyclias typically grow as epiphytes or lithophytes, often in exposed situations, at low to moderate altitudes. Consequently, they do best when grown in free-draining media under bright light (though generally not full sun) and with plenty of air movement. Indoors, try growing plants on a south-facing windowsill and/or close to artificial lights. Consider putting plants outdoors in summer. In my greenhouse, I have found that the light diffusion offered by 8 mm twin-wall polycarbonate and a thin layer of dirt is sufficient for most species, without need for additional shade cloth.

Potting media should be open and long lasting. A combination of bark chunks and coarse perlite is the most common traditional choice, but other inorganic components (gravel, stalite, aliflor, scoria, etc) can also be helpful. In my greenhouse, plants do very well in pure scoria (red lava rock), although salt buildup may be a problem in areas with hard water.

Many Encyclia species are adapted to intermittent or seasonal drought, so allow the pot to dry almost completely before re-watering. I find plants easier to manage in terracotta pots than in plastic pots, because rotting roots are the inevitable consequence when potting mix stays wet for too long. Plants can also be grown in plastic or hardwood baskets, or mounted on cork or hardwood. Treefern mounts often stay too wet.

Repot when you see new root growth, not when you see new pseudobulb growth. In some species, roots are produced on immature pseudobulbs, but others root on mature pseudobulbs shortly before flowering. Encyclia cordigera, for instance, initiates new pseudobulb growth in late spring, has a dormant period when the pseudobulb is mature, and finally produces new roots in late winter/early spring shortly before flowering. If you repot E. cordigera in spring and damage the existing roots, the new growth will struggle for almost a year before forming new roots.

Pests and Diseases

Apart from rots associated with cold and overwatering, Encyclia plants are generally free of diseases. They are susceptible to insect pests, though. Aphids, mealybugs, and soft brown scale can badly damage inflorescences, but they will not usually kill a plant. They can be controlled without damaging tender flower buds by spraying with horticultural soaps. Bees can be pests when plants are grown outside, because they will efficiently pollinate all the flowers on your favorite plant. The pollinated flowers rapidly fade and lose their fragrance. To avoid this problem, move flowering plants indoors or enjoy them on a screened porch.

The worst enemy of cultivated Encyclia is boisduval scale (Diaspis boisduvalii). An untreated infestation of this species will disfigure and eventually kill most Encyclia plants. These scale insects are common in commercial nurseries that grow orchids with hard pseudobulbs, particularly Cattleya and related orchids like Encyclia, and even when growers have an active control program it is difficult to entirely exterminate the little pests. Great care should be taken when introducing new plants to your collection. Be very suspicious of plants with yellow patches on their foliage, and closely examine the undersides of leaves for fluffy clusters of males. Peel off the dry, papery bracts on old pseudobulbs to make sure that scale aren’t hiding underneath.

In a small collection, it may be possible to control boisduval scale by spraying with relatively innocuous substances (horticultural soap, oils, 70% isopropyl alcohol, etc), but repeated spraying will be required to achieve control. Wipe down leaves after spraying to dislodge the female shells that protect eggs. In a large greenhouse, the big guns (i.e. systemic pesticides) will probably be required.

True confession: I failed to control a boisduval scale infestation in my collection. Ten years ago, my orchid collection was about 80% Cattleya and Encyclia species, including some very unusual and beautiful plants. Boisduval scale got into the collection, probably through a plant purchased on eBay, and I hesitated to use systemic pesticides. We had young children, and my greenhouse is close to our vegetable garden. With my professional background in genetics and neurobiology I am aware of the limitations of safety testing and sensitive to the possibility of subtle developmental and neurological effects in humans exposed to pesticides that target the insect nervous system. Since orchids are a hobby, not my profession, I decided that I would rather cull badly infested plants and grow something else than rely on highly toxic pesticides. Today, there is not a single surviving Cattleya in my collection, but I still grow a handful of Encyclia species. Some have survived multiple scale infestations controlled by frequent spraying with 70% isopropanol and/or insecticidal soap. Surprisingly, a few species have remained completely untouched by the scale insects, even when grown alongside–or even touching–infested plants.

In my collection, Encyclia cordigera (left foreground) has been completely immune to boisduval scale, while E. randii (center) and E. profusa (right) were badly infested and have been culled.

But enough gloom and doom. Hopefully you will never see boisduval scale on your plants.

Up next: some beautiful Caribbean Encyclia species.

Midwinter flowers

Yes, I know that in the United States the winter solstice is considered the first day of winter, but you can’t convince me that the shortest, darkest day of the year isn’t midwinter. My garden, which today sat under low grey clouds, is at its lowest ebb, but in my greenhouse there are at least a few flowers to brighten the gloom. Here are three:

Paphiopedilum gratrixianum

P. gratrixianum is one of the plain-leaf slipper orchid species that have glossy, rather elegant flowers, one per inflorescence. It is closely related to P. villosum (Photo 6 here) which is also flowering this week.

Sinningia bullata

S. bullata was described in 2010 from material collected in Santa Catarina, Brazil, surprisingly recent for such a striking plant. Its species name refers to the bullate (blistered) foliage, but the bright flowers are what draw the eye at this time of year. Unlike many Sinningia species which require a dry winter dormancy, S. bullata seems to grow year-round. New stems sprout from the tuber almost immediately after the old ones die back, and even when not in flower the plant is attractive for its neat foliage with an attractive texture up top and soft woolly indumentum underneath.

Columnea microcalyx (syn. C. gloriosa)

Like S. bullata, C. microcalyx is a member of the Gesneriaceae, the african violet family. This species is an epiphyte from Central America, and its long, trailing stems are best managed in a hanging basket. My plant, started from a cutting about 18 months ago, is covered in buds and will probably look spectacular in about 4-6 weeks, but I couldn’t resist taking a picture of one of the first flowers to open. This species is usually labeled C. gloriosa in cultivation, but Kew considers that name to be a later synonym.

Six on Saturday #68 (December 4, 2021)

It has been almost six months, more than a full season of change, since my last Six on Saturday post! Our first freeze was on November 14, so despite the fact that it is 70 F (21 C) outside this afternoon, the garden is in its winter form.

1-5. memento mori and the promise of rebirth

Fallen leaves of Magnolia macrophylla (bigleaf magnolia). The oak leaf at center gives a sense of scale.

The stems and fruit of Musa velutina (pink banana) do not tolerate any frost, but the rhizomes will sleep peacefully under the soil until next year.

The fluffy seed heads of Vernonia glauca (broadleaf ironweed; see picture #3 here) are why this plant is close to becoming a weed in my garden..

At this time of year, it’s easy to see why Iris domestica has the common name “blackberry lily”. See #6 here for flowers.

Allium tuberosum (garlic chives) is ready to take over the vegetable garden.

6. Winter greens in the vegetable bins

Not everything in the garden is dead.

The Propagator is the host of Six on Saturday. Head over there to see his Six for this week and find links to the blogs of other participants.

A modern vireya hybrid

Rhododendron praetervisum x ‘Doctor Hermann Sleumer’

As a complement to Rhododendron ‘Princess Alexandra’, the Victorian vireya that I wrote about in June, here is a more recent vireya hybrid. This plant is Rhododendron praetervisum x ‘Doctor Hermann Sleumer’, so its parentage is R. praetervisum x (konori var phaeopeplum x zoelleri). R. zoelleri has been known since the 1890s, but the type specimen of R. konori var. phaeopeplum was collected in 1939, and the type of R. praetervisum in 1965 [1]. The cross was made by Richard Currie in his New Zealand garden, presumably in the late 1970s or 1980s. One plant of this cross was registered as Rhododendron ‘Cheeky’ but I am not certain if my plant is a division of that cultivar or a sibling.

I previously grew a plant of R. praetervisum, but it never thrived, flowered infrequently, and died after about five years. I’m hopeful that this plant will exhibit hybrid vigor and, perhaps, inherit heat tolerance from R. zoelleri (native altitude range sea level-2000 m [1]). I purchased it in April, and it grew well in my shade house during the summer and has already flowered twice.

Incidentally, Hermann Sleumer was a botanist at the Rijksherbarium in Leiden. He described hundreds of new vireya Rhododendron species in the 1950s and 60s, making him one of the most important names in the modern era of vireya cultivation. Both R. praetervisum and R. konori var phaeopeplum (as R. phaeopeplum) were described by Dr Sleumer.

Reference

1. Argent, G. (2015) Rhododendrons of subgenus Vireya, 2nd edition. Royal Botanic Garden, Edinburgh.