Selected Species - by Peter Taylor

Maxillaria pseudoreichenheimiana (Dodson)

The genus Maxillaria is one of the most widespread of New World orchids and contains some wonderful species which, over the past few years, have been eagerly sought by species enthusiasts.  Of this diverse group of plants, one of the most singlular and charming is the selected species for this month, Maxillaria pseudoreichenheimiana.

I first saw this species among Philip Altmann's plants and, on first glimpse, thought Philip had either flicked a paint brush with white paint over it or, with some horror, that he was in possession of a plant with an interesting new virus!  Thankfully, I was wrong on both counts and I now grow the species as one of my special favourites.

The illustrations accompanying this article, both by David Banks, clearly illustrate the most obvious feature of the species, that which caused my initial concern - the wonderful leaves, dark green splashed with white/silver dots.

However, before we look at this specific plant, a little about the genus to which it belongs.

The Spanish botanists Ruiz and Pavon first described the genus in 1794 based on plants they discovered in the Peruvian Andes in 1777-88.  Many species became lumped into the genus Maxillaria and the great botanist Lindley published in the Botanical Register of 1843 a revision of the genus.  He formed new genera such as Lycaste, Paphinia, Scuticaria etc but Maxillaria still retained many species; most authors today allow for at least 300 species.

Still, however, some confusion exists as many species which were sent by different collectors to herbariums in England, Europe and America were accorded different names when in fact they were the same species.  For example, M. grandiflora, and botanically obscure and rare species, is often confused with M. venusta and M. eburnea.  I particularly like the derivation of the generic name. It comes from the Latin "maxilla" and refers to the jawbone appearance of the column and lip of several species which resembles the jaws of an insect.  As Rentoul (1982) notes, in some species even the petals hold a rather menacing "pincer-like" jaw appearance.  Maxillaria picta and M. nigrescens are two species in which this characteristic is easily seen.

Veitch (1887) provides an excellent brief description of Maxillaria plants:

• The pseudobulbs are more or less flattened with one or more sheathing, acuminate brown spathes on the sides.

• The leaves are variable in size and shape but always persistent, leathery in texture and usually dark green.

• The scapes are always one-flowered and clothed in four to six or more bracts which become brown before the flower fades.

The genus is distributed through Colombia, Venezuela, Ecuador and Peru and is both epiphytic and lithophytic in habitat.  Some species can withstand very low temperatures, down to 5⁰C - others like the warmer-growing magnificent species M. sanderiana prefer a winter minimum of about 15⁰C.

It is important to ascertain the natural habitat of Maxillaria species before you attempt to cultivate them.  I have found that the "coolest growing" Maxillaria species in my collection is the pretty M. picta (confused with M. prophyrostele in many collections), the most difficult to flower is M.sophronites and the largest flowered is M. sanderiana.

If you are lucky enough to have this species in your collection be aware of its flowering habit.  Flowers are produced from the base of the pseudobulbs and often grow downwards.  Hence, wire basket culture in sphagnum moss is the ideal.  The root system of many Maxillaria species is rather fine, invasive and easily over-damaged when repotting.  Care needs to be exercised here, especially as some of the larger-flowered species are of considerable cost to purchase!

An excellent brief chapter on Maxillaria is contained in the late Jim Rentoul's Growing Orchids - Book 3, first published in 1982. I urge all Maxillaria enthusiasts to read it.

Maxillaria pseudoreichenheimiana does not have flowers that rival the size of M. sanderiana nor flowers as colourful as M. picta or M. nigrescens but it is prolific in flower production and rewards the grower with two good "crops" a year.  The greater the number of rather delicate pink, white and yellow flowers makes a wonderful display.  David Banks took these photographs in 1999 when my plant was small and flowering for the first time. It is now considerably larger and this year had 80 flowers.  It blooms in winter and late spring.

The species is found in western Ecuador and Colombia at elevations of 350 - 1600m and, while considered a warm epiphytic grower, I find it does well with a winter minimum of 12⁰C in the Hills district of Sydney. Humidity and moisture are needed.

In 1980, Dodson separated this species as a valid entry from the long-known M. reichenheimiana.  I do not have this species but believe it has a different geological location (Costa Rica, Peru, Guyana and Venezuela).

Even if the plant did not produce its lavish displays of flowers, I would grow it for the beauty of its leaves. They are quite stunning, very different from the normal variegated leaves seen in some orchid genera.

If you have the species, grow it in a sheltered position - sunlight soon damage these leaves! The wonders of evolution again.  In the process of natural selection, I wonder what particular force caused these leaves to evolve this way. How has this made M. pseudoreichenheimiana better adapted to its environment?

© Peter Taylor and Australian Orchid Council Inc 2002

Originally published in "Orchids Australia" August 2002.