Dendrobium lindleyi is a dwarf epiphyte whose native range extends from Bangladesh and Assam through Southeast Asia to southern China. This species, called D. aggregatum in older literature, often seems to turn up in books about orchid growing as an example of a species requiring a distinct dry dormancy to trigger flowering. Apart from that one quirk, it is relatively easy to grow. D. lindleyi is often grown in baskets or mounted on cork bark, but my plant is potted in Aliflor (expanded clay aggregate) which dries very rapidly after watering. During the summer, while the new pseudobulbs are growing, I hang the pot from the edge of my shade house where it receives full sun for much of the day. As long as the weather stays dry, I leave it out in autumn until the nights drop into the mid 40s F (6-8 C), but I don’t let it stay out in cold wet weather. Back in the greenhouse, I hang it high in the rafters on the side without shade cloth and basically forget about it for most of the winter. If the pseudobulbs shrivel, I might give it a little water every six weeks or so, but mostly it survives on humidity. Et Voila. This is the result.
It’s hard to believe that it has been three months since I last managed to get a Six on Saturday post together. The past week has been gloomy and wet outside, so here are six plants that are currently flowering in my greenhouse.
1. Paphiopedilum Fanaticum
Paphiopedilum x fanaticum is the natural hybrid of Paphiopedilum malipoense and P. micranthum. When the same cross is produced in cultivation, the plants are designated Paphiopedilum Fanaticum. This isn’t the greatest photo–light levels were low, and the flower is still opening–but I think you can see that the plant is aptly named. Anyone who is subject to orchidelirium will likely be a fanatic for Paph. Fanaticum.
2. Epidendrum cf. schlechterianum
E. schlechterianum is miniature orchid found from Costa Rica to northern South America (Peru, Colombia, Brazil). Alternatively, E. schlechterianum grows only in Panama, and a group of closely related species–E. congestum, E. congestioides, E. oxynanodes, E. schizoclinandrium, E. serruliferum, and E. uleinanodes–are found elsewhere. It all depends on which botanist you believe. In any case, this is a bizarre little plant with flowers that are almost the same color and texture as the semi-succulent leaves that cover its creeping stems. It grows well mounted on a chunk of treefern fiber and watered once or twice a week.
3. Dendrobium speciosum var. pedunculatum
Some forms of the Australian Dendrobium speciosum grow so large that a forklift is required to move them, but D. speciosum var. pedunculatum is a dwarf variety. My plant has been growing happily in a 4-inch (10 cm) diameter terracotta pot for the past five years, and its pseudobulbs are only slightly larger than my thumb. In summer, it lives outside in almost full sun. In winter, I keep it in the brightest end of the greenhouse and reduce watering to once every two or three weeks.
4. Utricularia sandersonii (Sanderson’s bladderwort)
Although its flowers look vaguely orchid-like, Utricularia sandersonii is a terrestrial bladderwort, a carnivorous member of the family Lentibulariaceae native to South Africa. It grows in saturated soils, where its underground bladder traps can capture and digest protists or rotifers that are small enough to swim between the soil grains. The leaves of U. sandersonii are a couple of millimeters long, and the flower, which looks a bit like a long-tailed rabbit (or maybe a bilby), is about 1 cm from top to bottom.
I grow U. sandersonii in a small pot sitting in water almost up to the surface of the soil (a mix of peat and silica sand). After a few years, it forms a thick tangle of stolons and starts to deteriorate, perhaps because the supply of protists or trace elements in the soil has been exhausted. At that point, propagation is simply a matter of tearing off a chunk of soil/stolons and using it to inoculate a new pot of soil.
5. Hippeastrum striatum
H. striatum is a smallish species from southern Brazil. Its bulbs, leaves, and flowers are all much smaller than the big hybrid hippeastrums that are sold as “Amaryllis” at Christmas time, and I think it is better suited to cultivation in pots.
6. Cyrtanthus (species? hybrid?)
This plant grew from seed that I purchased as Cyrtanthus stenanthus, but it appears to have been mislabeled. It seems to want grow in winter/spring and goes dormant in hot weather.
Six on Saturday is hosted by The Propagator. Head over there to see his Six for this week and to find links to the blogs of other participants.
Half the fun of trading or giving away plant cuttings and divisions is seeing what other people can do with the same plants that I grow. For the past ten years, I have been growing Clusia orthoneura, a strange epiphytic shrub from South America. My plant resides in a 14″ terracotta bulb pan and is a semi-bonsai. Every year, I put it outside for the summer, where its branches sprout aerial roots that reach the ground and dig in by the end of the summer. Each autumn, I cut back those roots and much of the new foliage, so it will fit back into my greenhouse. As a result, it remains almost the same size from year to year.
About five years ago, I rooted a small cutting and gave it to John Stanton, owner of the Orchid Trail nursery in Morrisville, NC. John put the cutting in an 8″ diameter pot, and sat it on one of his greenhouse benches. In the large commercial greenhouse, it wasn’t moved every year, and roots that grew down through the bench weren’t disturbed. Also, John is an exceptionally good grower.
Earlier this week I stopped by the Orchid Trail in search of a particular slipper orchid species, and John showed me his Clusia.
The plant rises about six feet above the greenhouse bench and is equally wide.
Under the greenhouse bench, the roots resemble those of a mangrove or a strangler fig.
The pot is still visible, but most of the plant’s bulk completely bypasses it. At this point, the pot could be cut away without bothering the plant at all.
It’s almost unrecognizable as the same species as the stunted little thing in my greenhouse.
“What’s in a name? That which we call a rose by any other word would smell as sweet.” –William Shakespeare
Once upon a time, there was a small genus of orchids called Schomburgkia whose species grew in the Caribbean islands, Central America, and South America. Schomburgkia was divided into two subgenera distinguished by pseudobulb morphology: some species had solid pseudobulbs, while others had hollow pseudobulbs inhabited by ants. All of the species had smallish flowers clustered at the end of a long inflorescence.
In the 21st century, DNA sequencing has demonstrated that the two groups of Schomburgkia aren’t very closely related to each other . The ant-house species were reclassified into genus Myrmecophila, an old name that previously hadn’t been widely accepted, and the solid-pseudobulb Schomburgkia became part of the genus Laelia. Bummer. I kind of liked saying “Schomburgkia.”
This orchid came to me labeled Schomburgkia schultzei, which would make it Laelia schultzei now. Unfortunately, the flowers don’t match that species. Based on the photos in volume 3 of Carl Withner’s The Cattleyas and their Relatives, I think it may be Laelia undulata (formerly Schomburgkia undulata), a species native Costa Rica, Colombia, Venezuela, and Trinidad . According to Withner, L. undulata grows in open forest with a pronounced dry season and is found in both lowlands and highlands up to about 975 meters. As one might expect, based on this habitat, the plant has well developed pseudobulbs and rigid foliage that resists desiccation and sunburn.
I grow my plant in an 8″ square wooden basket, empty except for a couple of chunks of treefern fiber. I water it about once a week, year round, and hang the basket high in the greenhouse where it gets bright light and dries rapidly. When it starts to spike, I lower the basket to the bench, because the stiff inflorescence extends a good six feet before producing its cluster of flowers.
1. Van den Berg, C., Higgins, W.E., Dressler, R.L., Whitten, W.M., Soto-Arenas, M.A., and Chase, M.W. (2009) A phylogenetic study of Laeliinae (Orchidaceae) based on combined nuclear and plastid DNA sequences. Annals of Botany 104: 417-430
2. Withner, C.L. (1993) The Cattleyas and Their Relatives: Volume III. Schomburgkia, Sophronitis, and Other South American Genera, Timber Press, Portland, Oregon.
We’re now in that liminal time when every frost could be the last, but we won’t know for sure until several more weeks have passed. Yesterday was about 75 F (24 C), but snow is possible tonight.
In the woods, native redbuds (Cercis canadensis) and invasive Wisteria sinensis are in full bloom, and the dogwoods (Cornus florida) are just getting started. In the garden, the first azalea flowers are opening, but most color still comes from spring bulbs.
Here’s what was going on in the garden and greenhouse this week.
1. Tulipa sylvestris (Woodland tulip)
Last autumn, I planted some bulbs of Tulipa clusiana var. chrysantha and Tulipa sylvestris. T. clusiana is supposed to be one of the best tulips for naturalizing in this climate, but I’m not sure how T. sylvestris will do long-term. It’s possible that this floral show will be a one-time event if T. sylvestris doesn’t tolerate heat and humidity.
2. Narcissus willkommii
Another new addition to the garden. N. willkommii is one of the smallest Narcissus species, so I have planted it more as a curiosity than as a major player in the spring flower beds. I scattered the bulbs at the edge of a few beds and in dry soil under some hickory trees where they won’t be smothered by more robust plants. The only other things growing around them are some Cyclamen hederifolium that will be going dormant soon.
3. Trillium luteum
Along the woodland path, a single T. luteum has persisted for the past seven years in soil that is really too dry and infertile for most woodland wildflowers. I have a tendency to forget about spring ephemerals during the large portion of the year when they are invisible, so the little red cedar seedling makes a convenient marker when the trillium is dormant.
4. Rhyncholaelia digbyana
In this season–when the sun is rising higher in the sky, but the deciduous trees are still leafless–the greenhouse sees the most intense light of the year. Not surprisingly, this is the blooming season of Rhyncholaelia digbyana, a central American species that requires intense light and hot, dry conditions for best growth. My two plants are grown at the brightest end of the greenhouse in small terracotta pots with chunks of scoria and aliflor as the growing medium.
R. digbyana is one of the basic genetic building blocks of cattleya hybrids, and its fantastic, deeply incised labellum is the source of the large, frilly lip beloved of hybridizers. The flowers also have a pleasant lemony fragrance. Unfortunately, R. digbyana usually produces only one short-lived flower per growth, and those traits are also inherited.
5. Sarcoglottis sceptrodes
A terrestrial orchid from central America. I think the flowers look like the heads of sauropod dinosaurs.
6. Enanthleya Bob Gasko
This hybrid is (Guarianthe aurantiaca x Encyclia incumbens) x (Cattleya harpophylla x Cattleya neokautskyi), so three of its four grandparents have bright orange flowers. Vegetatively, it is intermediate between a Guarianthe and an Encylia, with cigar-shaped pseudobulbs that flush red in bright light and two stiff leaves on each pseudobulb.