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

Picture of backlit Encyclia cordigera flowers
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).

Picture of Encyclia cordigera plant
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.

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.

Picture of Encyclia tampensis in the wild
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.

Flowers of Encyclia cordigera, Encyclia randii, and Encyclia profusa
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 that are worth growing.

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

Paph_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

Sinningia_bullata1

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.

Sinningia_bullata2

Columnea microcalyx (syn. C. gloriosa)

Columnea_microcalyx2

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.

Columnea_microcalyx3Columnea_microcalyx1

Six on Saturday #66 (May 22, 2021)

After one of the mildest and wettest winters on record, we have had one of the driest springs. This week, the switch flipped to “summer” and with the increasing heat and humidity, we can perhaps hope for a thunderstorm or two.

Here is some of what is growing and flowering in the greenhouse and garden this week.

1. Medinilla ‘Royal Intenz’

Medinilla_Royal-Intenz

Beautiful plant, silly name. This new cultivar is apparently a hybrid, but it’s not clear what species are in its background. Definitely Medinilla magnifica, because M. ‘Royal Intenz’ looks rather like a very intensely colored, compact M. magnifica. The abstract of the plant patent simply refers to its parents by ID number, not species or cultivar names, and there doesn’t seem to be any way for me to find out exactly what I am growing. It’s somewhat annoying.

In any event, M. magnifica and related species–and by extension M. ‘Royal Intenz’–are epiphytic shrubs from the Philippines which adapt well to cultivation in a warm greenhouse or bright, humid windowsill. Logee’s offered M. ‘Royal Intenz’ briefly last year, and I’m glad I got an order in before they sold out.

I’m starting to see some fungal spotting on the foliage, perhaps due to water dripping from overhead Nepenthes plants. I think it’s time to move it to a brighter and drier spot in the greenhouse, or perhaps outside for the summer.

2. Pearcea rhodotricha

Pearcea rhodotricha flowers

Pearcea rhodotricha is a gesneriad from Ecuador with flowers that are probably the closest that I have ever seen to true black. Adding to its overall bizarre appearance, the stems and undersides of the leaves are densely covered with red hairs (hence “rhodotricha”) not unlike those of a tarantula.

A picture of the stem of Pearcea rhodotricha

3. Corytoplectus cutucuensis

A picture of the berries and foliage of Corytoplectus cutucuensis

Another Ecuadorean gesneriad, Corytoplectus cutucuensis has insignificant yellowish flowers. It’s the shiny black berries, sitting within long-lasting red bracts, and the beautifully variegated foliage that make it worth growing. Both this species and the previous are easy to grow from cuttings and appreciate a shady humid environment.

4. Encyclia Gail Nakagaki

Flowers of Encylia Orchid Jungle

Encyclia Gail Nakagaki is Encyclia cordigera x Encyclia alata (see below), and you can clearly see its parentage in its flowers. E. cordigera var. rosea gives the beautiful purple color and hooked tepals while E. alata contributes the striped lip and pale tepal bases. The fragrance of this orchid hybrid is fantastic.

enc_alata1
An old photo of an Encyclia alata in my collection

5. Tradescantia ‘Osprey’ (hybrid spiderwort)

Flowers of Tradescantia 'Osprey'

I suppose I ought to have at least one outdoor flower in my Six. ‘Osprey’ is a Tradescantia x Andersonia cultivar, but its pastel flowers are much more restful than the hot color of ‘Sweet Kate’ or ‘Concord Grape’ (see photos 2 and 3 of Six on Saturday #44). For some reason, it isn’t readily available at local nurseries, and I had to mail order this plant. It has doubled its size in a year, so maybe it will be large enough to divide and spread around the garden this autumn.

6. Ipomoea batatis (sweet potato)

sweet_potatoes

Slips from some ‘Beauregard’ sweet potatoes that we grew last year are almost ready for planting. Once the slips are about four inches long, I break them off the tuber and put them in a jar of water. They root in a few days. I only sprouted a couple of tubers for fun, but now I wish I had started more. For some reason, I haven’t been able to find slips in local garden centers yet this year.

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.

Paphiopedilum Johanna Burkhardt

Paph_Johanna-Burkhardt

I have previously written about two fine old primary hybrids made with Paphiopedilum rothschildianum: the Victorian P. Lady Isobel and P. Saint Swithin. Here is a modern one, and it may well be the best.

Paphiopedilum Johanna Burkhardt is P. rothschildianum x P. adductum, and it was registered in 1994. My plant was made using P. adductum var. anitum as the pollen parent, and the results are spectacular. P. rothschildianum has contributed flower size, number, and overall form, while genes from the very dark P. adductum var. anitum have produced a dorsal sepal, petals, and pouch with dark reddish-brown markings on a yellow background. P. adductum var. anitum has also reduced the overall size of the plant, without affecting flower size; this plant has about half the leaf-span of my other P. rothschildianum hybrids, but its flowers are just as large, if not larger. A Google search for this grex will turn up pictures of other clones, many of them awarded, with huge, muscular-looking flowers and dorsal sepals that are almost black.

P. adductum var. anitum is sometimes considered a separate species, P. anitum, in which case this hybrid would be P. Wössner Black Wings (P. rothschildianum x P. anitum). From a horticultural point of view, there’s something to be said for distinguishing the dark plants made with P. adductum var anitum from those made with lighter colored P. adductum clones. However, the International Orchid Register lists P. Wössner Black Wings as a later synonym of P. Johanna Burkhardt, and both the Kew World Checklist of Selected Plant Families and a recent checklist of the genus Paphiopedilum (Koopowitz, H., 2018, Orchid Digest 82: 178-235) consider P. anitum to be a synonym of P. adductum.

Eight hybrids using P. Johanna Burkhardt as a parent have been registered, but none of the photos I have seen suggest that they are any better than–or even as good as–their parent. I’d go so far as to say that in this group of orchids, the primary hybrids are almost always better than complex hybrids. After more than 120 years, P. Lady Isobel and P. Saint Swithin are still well worth growing, and I suspect that the same will be true of P. Johanna Burkhardt in another century.

Six on Saturday #64 (March 13, 2021)

What a difference a few weeks makes. This week has been brightly sunny, and the high temperature was about 80 F (26.5 C). The spring bulbs and hellebores are nearing their peak, the garden is perfumed by Edgeworthia chrysantha, Lonicera fragrantissima, and Osmanthus fragrans, and the fence lizards are skittering about in the leaf litter.

1. Cypripedium formosanum (Formosan lady’s slipper orchid)

Cyp_formosanum

After three years, my C. formosanum is still going strong. I think this year’s flower is the nicest so far. The plant is in an 8-inch diameter pot with a mix of composted wood chips, peat, and stalite. It lives outside under shade cloth in summer and spends the winter on the floor of the greenhouse, near the cold draught from the imperfectly sealed swamp cooler.

2. Hellebore flowers

Hellebore flowers floating in a dish

The pure white flowers at center left and 5 o’clock are Helleborus niger. The large reddish flower at 10 o’clock is Helleborus x iburgensis ‘Anna’s Red’. The others are all seed-grown Helleborus x hybridus.

3. Narcissus ‘Odoratus’

Narcissus_odoratus

This is a dwarf tazetta Narcissus. According to various web sources, it was discovered somewhere on the Isles of Scilly by the horticulturalist Alec Gray. To my nose it is only faintly fragrant, despite the cultivar name.

4. Narcissus x odorus (Campernelle)

Campernelle

Narcissus x odorus is a centuries-old hybrid of N. jonquilla x N. pseudonarcissus. It has been grown in North Carolina since the colonial period. The blue-green foliage in the foreground is Tulipa clusiana var. chrysantha (see photo 2 here).

5. Cackleberries

eggses

The tiny dinosaurs have started laying, and between the five of them, we are averaging about four eggs a day! The very pale blue-gray eggses are from Hühnchen and Kuritsa. Dark brown with darker speckles is from Pollo, large brown from Kylling, and small, light brown from Frango.

6. Vegetable seedlings

A picture of Cypripedium formosanum

I handle the ornamental perennials, but vegetables are my wife’s domain–she’ll have more than a dozen different varieties of Asian greens and kale, along with tomatoes, malabar spinach, spigariello, lettuce, and a few annual flowers ready to plant out next month. The glow from her new LED grow lights makes our house look like something out of “The Amityville Horror” at night, but the seedlings seem to love it.

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.