Odontoglossums – John Gay
In the 7-8 years since John last covered the genus for us, many changes have resulted in classification within the oncidiinae subtribe (and, indeed, more are to come). The genus now consists of just over 50 species, which reside in the higher mountains (5,000’-10,000’) in tropical central and northern South America – approx 20deg N to 15deg S of the equator. More species are now being found as Bolivia becomes more open to access.
The genus was described by Humbolt, Bonpland & Kunth in 1815 with Odm. epidendriodes being the species type. The plants live in cloud forest, often in cool mist, but with good air circulation. Minimum winter temperature should be 10C with maximum summer temperatures around 20C. Humidity should be 80%, and they like to sleep with wet feet. They aren’t heavy feeders. Various potting mixes will suffice – John uses mainly douglas fir (6 parts) with some NZ sphagnum (1), sponge rock (1), and foam (1). Some natural hybrids do occur, generally with either crispum or luteopurpureum as a parent. Reference books on the subject are far and few between, but Oncidium/Odontoglossum Alliance by Baker & Baker is recommended.
John covered the genus (as it currently stands) with each species alphabetically;
albertiiis a new species described in 2006, with small spiky yellow brown flowers.
alvarezii is also new, with some debate as to whether it is a variety of tenue. It has pale green petals with brown marks, and a white lip with pink blotches
armatum (Ecuador) has yellow/brown star shaped flowers.
ariasii (Peru) is new, and is named after the owner of Peruflora (Manuel Arias). It has starry yellow/brown flowers with a white lip.
aspidorhynun (Columbia) has narrow starry flowers with a whitish lip.
aurarium (Columbia) has curly star shaped white petals, with blotches on the sepals.
blandum (Columbia & Ecuador) has miniature white flowers spotted with brown. Not at all a bland flower.
cirrhosum (Ecuador) is one of the most beautiful, with tiny white flowers marked with brown blotches. See back cover
constrictum (Venezuela) has narrow starry flowers of pale green & brown.
crinitum (Columbia) is a miniature with a fimbriated lip.
crispum (Columbia) is one of the best known of the genus, and is a mainly round flower, usually pink to white with blotches, but has been line bred to produce various colours including var. Xanthotes (white with a yellow lip) amongst others.
cristatellum (Ecuador & Columbia) is a dark coloured flower.
cristatum (Ecuador) is starry yellow/blown to red with a comparatively large pale lip, and can be starry (var. Furcatum).
crocidipterum (Columbia/Venezuela) is a starry shaped flower similar to cirrhosum, but can be browner.
cruentum is a fairly simple flower with brown inners to the petals, with yellow at the end. Oddly, this can sometimes produce 6 petals!
dracoceps (peru) is a new species with starry yellow flowers with simple central brown blotches.
epidendroides (Ecuador) is the species type. It is a cupped flower of yellow with brown blotches
gloriosum (Columbia) is a mainly white starry flower with red markings.
harryanum is a very colourful flower, often confused with wyattianum. The way to differentiate them is that harrryanum has recurved sepals, whereas wyattianum has fairly open sepals.
hallii (Ecuador) is a variable starry flower from white to yellow with brown markings.
juninense (Peru) is a plain starry flower of brown petals with yellow ends, and a longish lip.
kegeljani (Ecuador) has bright yellow/brown flowers.
lindleyanum (Ecuador/Columbia) is starry shaped yellow flowers with brown blotches.
lucianianum (Venezuela) has cupped white starry flowers with purple marks.
luteopurpureum (Columbia) has mainly brown star shaped flowers with some yellow. It is quite common, and has a tall spike.
micklowii has simple plain green flowers with some brown marks. Only 1 small plant is known at present at the Marie Selby Gardens.
mirandum (Columbia) has graceful starry flowers of light green with brown centres, and a narrow lip.
multistellare is an extremely variable plant that is described as a taxonomist’s nightmare. It has a slight similarity to a Brassia.
naevium (Venezuela) is a white – similar to cirrhosum.
navadense (Columbia) has starry brown with yellow flowers. It is quite rare.
nobile (Columbia) is quite similar to crispum, with a fine alba form. This species used to be known as pescatorei.
odoratum (Venezuela) is as the name suggests a fragrant flower like cirrhosum, but can vary to yellow.
portillae (Ecuador) has very spiky flowers of pale green & brown.
povidanum (Columbia) is a new species and has rounder flowers of small size on a good spike, which will reflower like a Phalaenopsis.
praenitens has small starry flowers.
praestens is a common species with variable curly star shaped flowers from white to yellow that can become fairly big.
ramosissimum (Columbia, Ecuador & Venezuela) is starry like cirrhosum.
reversum (Columbia) is a simple star shape.
rhyncanthum (Columbia) is a typical star shape of yellow with brown.
sceptrum (Columbia) is a rounded star shape like cristatum.
schillerianum (Venezuela) is a brightly coloured star shaped flower.
spectantissimum (Columbia) was formerly known as triumphans, and has variable fatter star shaped flowers.
subuligerum (Columbia) has simple plain green star shaped flowers.
tenuifolium (Venezuela) is a recent species of mainly yellow, and looks like a dancer with its fused sepals! see back cover
tenue (Ecuador & Peru) is a small and nicely coloured flower with a flamboyant lip.
tripudians (Columbia) is a typical odont – starry, yellow & brown.
velleum is a miniature plant with a cupped mottled flower with a large white/brown lip.
wallisii (Columbia) is a narrow star shaped flower that appears almost orange.
wyattianum (Ecuador) is a dark coloured flower with a big lip – similar to harryanum.
A very good talk, that ended with a good round of applause, and a few questions.