A second look at a neotropical blueberry

Here’s another picture of the Macleania species that I discussed in a post ten days ago.  As the flowers have aged, the color has changed significantly.

Here is what the flowers look like today:

macleania_sp
Macleania species aff. smithiana (H.B.G. 89922)

And here is what they looked like ten days ago:

Macleania 3

Here is the original post.

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Three orchids

Some years, the first daffodils bloom about now, but this year almost everything in the garden is either dead or in deep dormancy.  For a little floral color, I have to rely on my greenhouse.

Here are three orchids with nothing much in common except that they bloom now.

1. Mormolyca ringens

Morm_ringens

This little orchid from Mexico and central America blooms pretty much all year round, with a single flower on each wiry inflorescence.  Like a surprising number of orchids, M. ringens is pollinated by pseudocopulation.  In other words, it induces naive (or desperate) male bees to mate with its flowers [1].  The labellum of the flower resembles the rear end of a small red-and-yellow bee, and it even produces a scent that mimics the pheromones of virgin queens [2].  Drones that attempt to mate with the flower transfer pollen to and from the overhanging yellow column.

2.  Brassia species (spider orchid)

brassia2

Brassia orchids also deceive their insect pollinators, but the mechanism would probably be better described as “pseudo-predation” rather than pseudocopulation.  Brassia flowers are pollinated by spider-hunter wasps which attack and repeatedly sting the labellum, apparently mistaking it for the body of a large spider [3].

brassia1

I think this is probably the Mexican/central American B. verrucosa, but I am not certain. It has been suggested that there are actually two different species circulating under that name [3], and in any case, Brassia species all look very similar to my non-expert eye.

3. Broughtonia Jamaica Jester (B. negrilensis x B. ortgesiana)

broughtonia

This is an artificial hybrid of two Broughtonia species, the Jamaican B. negrilensis and Cuban B. ortgesiana which was registered by Claude Hamilton, a well known grower and hybridizer of Caribbean orchid species.

broughtonia 2

References

1. Singer, R.B., Flach, A., Koehler, S., Marsaioli, A.J., and Do Carmo E. Amaral, M. (2004). Sexual mimcry in Mormolyca ringens (Lindl.) Schltr. (Orchidaceae: Maxillariinae).  Annals of Botany 93: 755-762.

2. Flach, A., Marsaioli, A.J., Singer, R.B., Do Carmo E. Amaral, M., Menezes, C., Kerr, W.E., Batista-Pereira, L.G., Correa, A.G. (2006)  Pollination by sexual mimicry in Mormolyca ringens: a floral chemistry that remarkably matches the pheromones of virgin queens of Scaptotrigona sp.  Journal of Chemical Ecology 32: 59-70.

3. Pupulin, F. and Bogarin, D. (2005) The genus Brassia in Costa Rica: A survey of four species and a new species. Orchids 74 : 202-207.

A neotropical blueberry

Macleania 3
Macleania species aff. smithiana (H.B.G. 89922)

No bonus points for guessing the pollinator of this plant.  It has hot pink tubular flowers of heavy, waxy substance.  It has to be pollinated by birds, right?  If I tell you that it’s from South America, then it’s obviously hummingbird-pollinated.

Macleania–a genus in the Ericaceae, the blueberry/rhododendron/heather family–is a plant geek’s delight.   Macleania species are found in central and South America, generally in high altitude cloud forest. Many are epiphytes that produce lignotubers, swollen roots or stem bases that store moisture and nutrients.  Their tubular flowers come in shades of bright orange, red, and pink, highlighted with green and yellow, and their berries are often sweet and edible.

The label of the plant illustrated above, Macleania sp. aff. smithiana, indicates that it may or may not be the species M. smithiana.  It generally fits the description of M. smithiana, except that its flowers are pink/yellow instead of orange-red/green.  Since plant descriptions are generally based on a limited range of specimens, it may turn out to be a color variant of M. smithiana.  Alternatively, it might be a closely related species.  The “aff.” (affinis) in the label reflects that uncertainty.  It came with an accession number from the Huntington Botanical Garden (HBG 89922), so there’s a chance I may be able to find out more someday.

I purchased this rooted cutting in autumn, 2016, because it was advertised as originating from lowland forest near Esmereldas, Ecuador.  Most Macleania species in cultivation are from higher elevation and are therefore less likely to tolerate our long hot summers.  So far, the plant has performed well, producing clean new growth and blooming for the first time this month.  I am growing it in a mix of permatill and long-fiber sphagnum moss, outside under shade-cloth in summer and in a cool corner of the greenhouse in winter.

First bloom: Hippeastrum calyptratum

calypratum1
Hippeastrum calyptratum

It’s frigid outside, but with a little help from LP gas (OK, a lot of help), it’s the tropics in my greenhouse.  This week, the star is a seed-grown Hippeastrum calyptratum bulb, flowering for the first time four years after germination.

H. calyptratum is a very unusual amaryllid from the Atlantic Forest of southern Brazil, where it grows as an epiphyte on tree trunks. The pale green flowers are pollinated by bats and are often reported to produce a odor like burning plastic.  To my nose, they smell more like wet paint, but the fragrance is not very strong–at least not from this seedling.

calyptratum2

There are two (possibly three) other epiphytic Hippeastrum species.  I previously posted on H. aulicum when my plants bloomed in autumn.  The third epiphytic species, H. papilio is currently blooming a few feet away from the H. calyptratum, and a different clone bloomed earlier, at the same time as my H. aulicum.

IMG_3487
Hippeastrum papilio

The fourth epiphyte, H. arboricola, is rather mysterious.  It was apparently described from a single plant found growing on a fallen tree in a clear-cut forest and has not been seen since.  It is not clear if H. arboricola represents a distinct epiphytic species, possibly now extinct, or if it was a terrestrial species that was growing opportunistically on a tree.

H. aulicum and H. papilio are large, robust plants, very easy to grow in a mix of commercial potting soil and permatill (stalite).  When I tried that mix with H. calyptratum, the plants did well initially but later lost their roots.  In some cases, the entire basal plate rotted, destroying the bulb.  I now use a very open, wholly inorganic mix of scoria (red lava rock) and permatill in terracotta pots and have much better results. As befits an epiphyte, I plant the bulb high in the pot, with just a few large chunks of scoria holding it in place.  The roots are quite happy to wander around on the surface of the mix.

papilio-calyptratum
Hippeastrum calyptratum (left) and Hippeastrum papilio (right)

Assuming that my blooming plant is close to full size, the bulbs of H. calyptratum seem to be significantly smaller than those of H. aulicum and H. papilio, and the leaves are proportionally shorter and narrower.   H. calyptratum shares with its larger epiphytic cousins a growth cycle that is quite different than that of the Hippeastrum (“Amaryllis”) hybrids sold for forcing in winter.  H. calyptratum has a short dormancy in mid-summer, but it retains some of its leaves and does not want to be bone dry for long periods while dormant.  As temperatures cool in autumn, my plants begin growing again, and they continue producing new leaves intermittently through the winter.

Rubiaceous Ant Plants (Six on Saturday #17, November 25, 2017)

After a couple of weeks absence, here’s another Six on Saturday.  As with previous posts on Pachypodium and Nepenthes, I’m focusing on a single group of greenhouse plants this week.

platytyrea-mossman
Myrmecodia platytyrea (Mossman Gorge form) overflowing a 5-inch pot

The epiphytic myrmecophytes (ant plants) of the coffee family, Rubiaceae, are surely some of the strangest plants that grow anywhere in the world.  Their overall appearance is often grotesque: gray or silver or brown blobs with thick, armored stems and sharp spines derived from modified roots.  They cling to tree trunks or hang upside down below horizontal branches, looking like aliens that have inexplicably settled in an Asian forest.  And to top all of that, their real strangeness is hidden inside.  Soon after a seedling ant plant germinates, the hypocotyl–the stem below the cotyledons–starts to swell into a tuber.  As the plant grows, tissue within the tuber dies in a genetically programmed manner, first forming a hollow space and then expanding into a series of tunnels and chambers.  The tunnels are connected to the outside by entrance holes around the base of the tuber, and the chambers are often aerated by pores.

All of this baroque development is for the benefit of symbiotic ant colonies who set up housekeeping in the artificial nest that the plant has grown.  Both insects and plant benefit from the relationship.  The ants get a secure home, and the plant is fed by the ants.  The ants live in smooth-walled chambers and deposit leftover fragments of insect prey and other waste in chambers with wart-like excrescences on the walls.  As the waste decomposes, the plant absorbs nitrogen through the warts.

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Myrmecodia tuberosa cut to reveal interior chambers (a photo from my defunct ant plant website, ca. 1998)

 

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Closeup of chambers.  Arrows indicate two warted chambers.  Smooth chambers can be seen at the center of the slice.

The natural range of the rubiaceous ant plants extends from Thailand to Australia and east as far as Fiji, but the greatest diversity is found on New Guinea.  In the mid-1990s, when I first became interested in ant plants, only about five species were in cultivation, and they were very hard to find.  With some effort (i.e. obsessive searching), I managed to connect with a few other like-minded growers via email and traded seed and seedlings with the curators of several botanical gardens.  These days, the plants are (somewhat) easier to obtain, and a wider range of genera and species are in cultivation thanks to the efforts of a handful of hobbyists and nursery owners from around the world.  Several nurseries in Europe and the U.S.A. sell seedlings, and plants are occasionally available on eBay.

So without further ado, here are six (on Saturday) ant plant species:

1.  Myrmecodia platytyrea (Mossman Gorge form)

The plant shown at the top of this post is a very vigorous Myrmecodia descended from material originally collected in northern Queensland.  Like most of the rubiaceous ant plants in cultivation, M. platytyrea has flowers that self-pollinate, so seedlings remain true to type over multiple generations.  The Mossman Gorge form of M. platytyrea produces long, sharp spines and very vigorous roots that often invade the pots of its neighbors.  Its leaves are narrower and more succulent than other cultivated M. platytyrea descended from plants collected in New Guinea.

platytyrea-mossman-stem

The shield-like leaf bases on the stems of M. platytyrea are called clypeoli.  The spines bordering the clypeoli hide alveoli, pits in which the small white flowers develop and from which the orange fruit protrudes when ripe.

2.  Myrmecodia sp. “Pink Fruit”

pink-fruit

This species has very strong sharp spines and pink fruit.  It is commonly cultivated by ant plant enthusiasts, but its origins are obscure.  Possibly, it is M. tuberosa ‘Papuana’ which grows in New Guinea and northern Australia.

3Myrmecodia tuberosa

tuberosa

tuberosa-stem

This is the most variable and widespread Myrmecodia species, with a range extending from Malaysia to Australia.  The form shown here does not have strongly developed clypeoli, so you can easily see the elongated alveoli filled with papery bracts.

4.  Myrmephytum beccarii

myrmephytum

Myrmephytum is a genus of five species found in the Philippines, Sulawesi, and western New Guinea.  M. beccarii is from the Philippines, and was introduced into cultivation in the U.S. around 2006.

5. Hydnophytum moseleyanum

moseleyanum

H. moseleyanum is a lowland species from New Guinea and Australia.  Hydnophytum species usually lack spines and have many elongated branches without clypeoli and alveoli.  Their chambers are less complex than those of Myrmecodia.  Note the large entrance hole on the side of this tuber.  Above and left of the entrance hole, a patch of papery dead tissue is peeling away to reveal a new hole.

6.  Hydnophytum formicarum

A very variable and widespread lowland species from Thailand, Malaysia, and Indonesia.  Several different forms varying in size and color are in cultivation.

formicarum1
Hydnophytum formicarum.  A large form from Thailand with entrance holes generally restricted to the underside of the tuber.  The tuber is partially obscured by moss growing up its sides and is larger than it appears.  This plant is twenty-one years old and was the first ant plant I grew from seed.
cf_formicarum1
Hydnophytum cf. formicarum. A plant distinguished by its very broad leaves and smaller tuber with proportionally very large entrance holes.
cf_formicarum-Belum
Hydnophytum cf. formicarum from Belum rainforest, peninsular Malaysia.  This is a dwarf form with brown, flattened tuber and tiny leaves barely as long as those of the Thai form are wide.  Notice the the small entrance hole on the right and pores on the lumpy region at left.

So, that’s six rubiaceous myrmecophytes.  For more Six on Saturday that is perhaps a little less botanically grotesque, head over to The Propagator.