Selected Species - by Peter Taylor

Pescatorea coronaria Reichb.f. Pesc_coronaria.jpg - 0 Bytes

Since the mid 19th century there has been much confusion regarding exactly which genus the spectacular and horticulturally desirable orchids today known as Pescatorea best fit into. However, there has never been confusion regarding the desirability of the Pescatorea species.

The Pescatorea alliance includes orchids as Bollea species (one of the best is the blue Bollea coelestis), Huntleya species, Chondrorhyncha species and some would allow Zygopetalum, a close relative, to be part of the allowance. All the aforementioned genera contain some terrific species but, to my undoubtedly biased eye, the jewels of the alliance are the Pescatorea species and, of these, the species I have selected this month, Pestcatorea coronoria, has a singular beauty.

The genus Pescatorea is small, from 12-16 species, distributed from Costa Rica to Ecuador. The generic name is dedicated to M. Pescatore, a French patron of orchid species in the mid-19th century. Veitch writing 1887, lumps Pescatorea with a large group of now recognised genera into Zygopetalum but mentions that "as new species come to light from that apparently inexhaustible treasury of orchid life, the tropical region of Central and South America, the original lines of demarcation were much obliterated".

Confusion as to just which genus plants we now readily identify as Zygopetalum, Huntleya, Bollea and Pescatorea species was the order of the day.  Reichenback had by 1852 described the genus Pescatorea in the Botanische Zeitung and B.S. Williams in The Orchid Growers Manual listed 10 species and wrote a short cultural paragraph in 1885.

What characteristics allowed Reichenbach and others since (Garray 1969, Fowlie 1968) to identify Pescatorea as a separate genus?  A fine description of these characteristics is contained in The Manual of Cultivated Orchid Species (1981) by Bechtel, Cribb and Launert - "Pescatorea ... can be distinguished from Zygopetalum by its lack of pseudobulbs, from Chondrorhyncha by its clawed lip and from Huntleya by the lack of broad, projecting lateral wings at the column apex.  (It is) ... distinct from Bollea with which it frequently hybridises in nature, the latter (Bollea) having a lip which is fairly adnate and continuous with the column foot."

I guess that a quick layman's description of Pescatorea species would be of plants with fan-shaped leaves and short basal inflorescences with strikingly lovely flowers. As early as 1887, Veitch recognised cultural difficulty in growing Pescatorea species - "the disappointing experience of the past twenty years in the cultivation of the species - "the disappointing experience of the past twenty years in the cultivation of the species ... forbids the formulation of any course of treatment for them". One of the major problems encountered by early growers was the lack of information (often deliberately withheld by collectors and their employers in attempting to corner the market and inflate prices) regarding their location and environmental conditions in situ.

Williams (1885) soon realised a cultural requirement - "they are often killed by having too much heat. We find they do best in the cool end of the East India house with plenty of water all year round ... with good drainage".

We are now well aware of their in situ environment and desirable cultural conditions. The keys to culture are high humidity, very good air circulation and consistent yearly temperatures. Most species are located in wet moderate rainforests in which the climate varies little over a year. Luckily, most growers are able to provide the reasonable minimum (about 12OC) and maximum (about 30OC) temperature requirements. More crucial, I feel, are the required high humidity, constant moisture in the pot and good air circulation.

I have achieved best growth in the Pescatorea species I grow by using plastic pots with enlarged drainage holes in the bottom, "crocked" to about quarter-depth with broken polystyrene and sphagnum moss. This enables heavy watering and constant moisture that the fleshy roots of the species desire.

There are some wonderful Pescatorea species that are of relatively easy culture; it is just a matter of locating seedlings or plants - no easy matter!  Still, look out for Pescatorea dayana (white blooms with lovely purple-violet markings), Pescatorea klaochorum (beautiful large blooms, white with striking chocolate-purple tip to the sepals and petals) and Pescatorea cerina (the type species, white sepals blotched yellow-green white petals).

However, my favourite species if the one I have taken a little time to get around to - Pescatorea coronaria. It comes from Colombia where it inhabits the wet Andian uplands at elevations of 1240-1850m.  It particularly makes its home on the branches of mossy trees. The previously mentioned factors of high humidity, air circulation and wet roots with constant temperatures throughout the year are the favourite conditions.

The blooms are held on an axillary, single flower inflorescence and appear in the spring. They are of heavy texture, a dark garnet-red with an interesting "hairy" labellum.  They have a slgith fragrance. The accompanying illustration of my. They have a slight fragrance.  The accompanying illustration of my plant, taken by James Indsto, shows the quality of the species.

I am unsure of the fate of the wonderful species collection of M. Pescatore - perhaps dismantled after his death, perhaps neglected in the Franco-Prussian war of 1871, certainly I would think by now long forgotten. How appropriate, then, that the name of a French patron of orchid species should live on in the name of genus of very lovely plants.

 

© Peter Taylor and Australian Orchid Council Inc 2002

Originally published in "Orchids Australia" February 2002.