BARKERIA ORCHIDS

GENUS REVIEW

Heading photo Barkeria skinneri

INTRODUCTION

THE GENUS BARKERIA is a relatively small one, but one which contains strikingly attractive and relatively small growing plants. Many have trouble maintaining these plants in cultivation,and this and the cultural page for this genus hopes to provide some information to ensure the continued successful cultivation of these plants.

This article is not intended to be a series review, rather to gather together species and habitat information which may be of interest and assistance to growers interested in these plants.

THE GENUS BARKERIA Knowles and Westcott



These are comparatively small plants which can be difficult to grow unless the particular requirements of their culture are noted. Their bright attractive flowers produced from small plants make them desirable additions to a connoisseurs collection - or just anyone who enjoys attractive flowers.

Out of growth the plants just look like a clump of dry twigs, but in the spring new growths are produced which develop during the warm moist summer finally producing flowers in the autumn and early winter. The final period is drier, and the winters are very dry, when the plants loose their leaves, and are dormant. They grow on small shrubs, and on small branches of trees, with their roots freely exposed to moving air. Therefore a very open compost must be used, which will require heavy watering during the spring and summer, but which can be kept dry during the late autumn and winter while the plants enter their period of dormancy.

W.W.G. and May Moir in their book Laeliinae Intergenerics notes 'they are very dainty and make lovely hybrids. It is surprising for floriferous they are.' They have been hybridised with epidendrum, (bardendrum) brassavola (brassokeria) laelias (laeliokeria) cattleyas (cattkeria) and laliocattleyas (laeliocattleria) amongst others.

Dr Robert Marsh in his article Barkerias - The Shape of Things to Come (AOS Bulletin 56.5) notes that all barkeria species with the exception of Barkeria skinneri have flowers which tend to nod. The lateral sepals are reflexed behind (above) the lip, forming, together with the dorsal sepal and sometimes the petals, either a crown or a fan over the column and lip. Barkeria malanocaulon represents the extreme in this form, with all sepals and petals pointing upward above the downward directed lip, giving the impression of a 'shooting star'. In eight of the species, the petals rotate up to 180 degrees about their own axis, presenting their backs to the viewer. This is best illustrated by Barkeria lindleyana var. alba.

Dr Marsh also notes that the plants have cane like pseudobulbs, these varying from 25 mm to 300 mm in height. The apically produced inflorescences are erect or arching, and may be branched, depending on the species. The flowering stems of young plants and many clones of Barkeria uniflora frequently bear a single flower, but the inflorescences of most mature species will carry 6 to 20 flowers. Barkeria palmeri is capable of producing as many as 100 flowers on a fully branched inflorescence.

The genus barkeria was first described by Knowles and Westcott in 1838 and named in honour of George Barker of Springfield, England, who had imported a plant from Mexico. The showy and long lasting flowers made it instantly popular and in great demand among growers and collectors. However, we can only guess what species it was. Because of the unusual cultural requirements, barkeria perished soon in British collections.


In 1892 Reichenbach united the genus barkeria with epidendrum. However, controversy over this union has been almost constant since that date. Schlechter (1927) thought that the genus barkeria, although closely related to epidendrum, should be kept distinct. However, Ames, Hubbard and Schweinfurth (1936) reunited the genus barkeria with epidendrum. Williams (1951) followed the same route as did Ames and Correll in 1952.

L.B. Thein and R.L. Dressler re--examined the taxonomy of barkeria in 1970 and came to conclusions which agreed with the views of Schlechter. They suggested that the genus barkeria is more closely allied to the genus Caularthron (still known by most collectors as Diacrium). The relationship with Caularthron was suggested by the general shape of the flowers, widely spreading fleshy column wings and structure of the rostellum. Recent detailed study of the epidermis of the leaves has also shown the genus Barkeria to be clearly differentiated from the genus Epidendrum

The total number of known species is around 14. The centre of distribution seems to be in Guerrero, Mexico and adjacent states. However, many of the known species extend much further south. Barkeria chinensis seems to extend into Panama, and the very showy Barkeria spectabilis is known from Mexico, Guatemala and El Salvador.

Apart from Barkeria spectabilis which is found at 1700 to 2150 metres altitude, the members of this genus come mostly from intermediate to low altitudes, and, thus, respond to intermediate to warm temperatures. the abaove two linkis take you to general habitat descriptions of the lowland rainforest and foothill mountain habitat pages, which can be usefully referred to.

The species are briefly listed and described. This is largely taken from the review of the genus completed. by Federico Halbinger and George C. Kennedy published in the Orchid Digest March/April 1980. The notes also include some interesting and relevant data on habitats.

The species

Eric Christenson has provided an updated lsit of species, and this is available on a separate page.
CLICK HERE


a.
Barkeria barkeriola Rchb.f.

This species grows on low shrubs at altitudes ranging from sea level up to 1000 metres. The plant is somewhat diminutive version of Barkeria uniflora but can be readily distinguished from that by fleshy wings on the column, which is widest about the middle and the sac-like nectary. Sepals are also longer than the petals.

b.
Barkeria chinensis (Lindley) Thein and Dressler

The first plants shipped from Guatemala to England were labeled incorrectly as being from Hong Kong, and this confusion gave the name 'chinensis'- 'of China'.

This species probably has the widest distribution of any of the species, ranging from Jalisco, Mexico, through to Panama at elevations from 500 to 1700 metres. The flowers usually only half open, with red lines and dotted veins on the lip. Vegetatively, the plants are identical to Barkeria palmeri and Barkeria naevosa thus only flowering plants can be identified.

c.
Barkeria dorotheae Halbinger

This was discovered by Dorothy O'Flaherty, a resident of Manzanillo, Colima, in 1975. The plants are lithophytic or epiphytic, slender and erect. Their growth habit is not unlike that of Barkeria palmeri, naevosa or strophinx. It is found in nature only over an area no larger than a tennis court, even though almost identical environmental conditions extend for many kilometers, both north and south of the type locality, and for tens of kilometers away from the ocean.

The flowers are very showy, appearing mainly in the months of May and June, but lateral spikes soon develop and flower through to July.

d.
Barkeria halbingeri Thien.

This species occurs solely as a lithophyte in the State of Oaxaca in Mexico, at about 1600 metres above sea level. It is extremely endemic and is known only from two localities. It is easily distinguished by its pale lilac colour, the wide -spreading fleshy green-lilac- yellow column, and it does not have a red lined design on the lip. It has been known for a long time as Barkeria malanocaulon.

e.
Barkeria lindleyana Bateman ex. Lindley.

e.1 Barkeria lindleyana subspecies lindleyana is found in Costa Rica in trees and shrubs in areas at an elevation ranging from 800 to 1600 metres. It is identified mainly by the lilac colour of the lip, the center white and the darker lilac spots on the apex, as well as by the three prominent keels of the lip. This has been incorrectly identified as Barkeria spectabilis, Barkeria cylotella and Barkeria malanocaulon, this in turn confused with Barkeria halbingeri.

e.2
Barkeria lindleyana subspecies vanniriana (Rchb.f.) Thien.

This species grows largely in the Mexico States of Michoacan, Guerro, Oaxaca and Puebla, and ranges in elevation from 1000 to 2000 metres. The flowers show the same characteristics and colour of those of B. lindleyana subspecies lindleyana, although show different and variable shapes in their lips. The main difference between the two subspecies lies in the different evolution of the plant habits in the two countries. The plants from Costa Rica grow in trees, and are slender and tall and have thin roots, and produce a new growth at the base of the first node. The Mexican plants usually grow on rocks and only occasionally on other media. Their pseudobulbs are shorter, their leaves are quite variable, and the roots are notably thicker and the new growth will generally appear from the second or third node, giving the plant a climbing habit.

f.
Barkeria melanocaulon Richard and Galeotti

An apparently exceedingly rare species from the Isthmus of Tehuantepec in the State of Oaxaca it grows over an altitude range of 100 to 300 metres. It is extremely endemic.

It is easily identified by the fleshy column which diverges from the lip and is the only known species of the genus with this characteristic. The flowers are relatively small, pale lilac and the extended lip is heart shaped, with purple red dots and streaks at the apex and shows three long yellow thickened keels.

g.
Barkeria naevosa (Lindley) Schlechter

It ranges in altitude from 400 to 1000 metres above sea level in the States of Oazaca, Guerrero and Michoacan in its native Mexico, where it is abundant. There is an extremely dark colour form, almost eye-searing magenta in colour. This species has exceedingly distinct characteristics. It is the only species of the genus with a strong and specific daytime fragrance. The reddish colour, the broad column, peculiar shape of the lip with the distinct design of the verrucose keels and lateral veins, and the ovary with a goitre-like swollen nectary. identify this species.

h.
Barkeria palmeri (Rolfe) Schlechter.

This ranges in elevation from 300 to 1300 metres altitude in the States of Colima, Jalisco, Mayarit, Sinaloa and Guerrero of Mexico. The inflorescence of a well grown plant is spectacular, with up to 100 pale lilac flowers Z0 to 30 mm across. The lip has a slightly tinted apical margin with dark lilac verrucose keels and veins. The column with its spreading membranaceous wings and sac-like nectary., are all well defined characteristics differentiating it from B. chinensis.


i.
Barkeria scandens (La Llav and Lexarza) Dressler and Halbinger.

This species is also known as Barkeria cylotella. It is found in the Mexican states of Michoacan, Guerrero and Oaxaca, at altitudes ranging from 1000 to 2000 metres. It grows on rocks, trees and small shrubs. This plants belongs to the 'Lindleyana' group because of the three keels to the lip, but can be readily distinguished especially by the colour of the flowers which are an intense magenta red, and the less prominent keels as compared with Barkeria lindleyana. Although this has been described as a sub-species of Barkeria lindleyana, the evidence that they are distinct species is that they grow together in Oaxaca and maintain their individual features and identity without hybridisation.

j.
Barkeria schoemakeri Halbinger

It is a highly endemic species only being found in the State of Michoacan at elevations of 620 metres near the village of La Huacana. It has the smallest flowers of the genus, approximately 16 mm in diameter. The plant can be readily distinguished by the proportionally large column, which diverges from the lip


with its basal portion adhering to the callus by 2 mm. The petals are shorter than the sepals. In spite of its size, Kennedy states it is a totally delightful flower.

k.
Barkeria skinneri (Bateman x Lindley) Richard and Galleotti

This species appears to be endemic to oak trees in the Mexican Chiapas and Guatemala at altitudes ranging from 1000 to 2000 metres above sea level. Small flowers are easily identified by their magenta red colour and 3 to 5 yellow keels on the sharply pointed lip.

This species is one of the numerous discoveries of the great orchid collector George Ure Skinner, who sent it to the botanist Bateman in 1835, in whose collection it flowered in 1836. James Vetch in his famous book notes that in its natural habitat in Guatemala it experiences a temperature range of 13 to 21 degrees Celsius through the year. It is described as being 'one of the handsomest of the winter flowering orchids.' It is said to have been nearly exterminated in its native habitats by the clearing of the forests for coffee plantations.

L
Barkeria spectabilis Bateman ex Lindley

This is the showiest of all the species in this genus, and one of the few that is not endemic to the states adjacent to Guerrero in west Mexico. It is known from Chiapas, Guatemala and El Salvador, where its natural habitat ranges in elevation from 1500 to 2000 metres. Unlike the other barkeria species, it is normally found growing on oaks.

For a great number of years it was classified with Barkeria lindleyana. Harbinger and Kennedy believe that the flowers of Barkeria spectabilis show sufficient unique characteristics to warrant its classification as a separate species. It is extremely variable having larger flowers u2 to 75 mm in diameter, and is extremely floriferous.


m.
Barkeria strophinx. (Rchb.f.) Halbinger

Long believed to be but a variety of Barkeria naevosa, a study of large flowering populations have indicated to those who have studied them that it is distinct from that species. The odour of this species is also distinctive, and the flowers, including the column, are all smaller and the general aspect and their colouring is said to be different. The number of flowers is different as is the mode of branching.

n.
Barkeria uniflora (La Llave and Lexarza) Dressler and Halbinger

This species has been widely known as Barkeria elegans. It is an epiphytic species found at altitudes from 1500 to 1700 metres above sea level in the Mexican states of Oaxaca, Guerrero, and Michoacan. The flowers are quite similar to Barkeria barkeriola, the sepals always being longer than the petals, and the petals always wider than the sepals, and the column has wide spreading fleshy wings. All plants were seen to be growing on twigs no more than 12 m~, in diameter, and their roots revel in moving air. To place these plants in pots is 'sudden death'.

Barkeria uniflora var. alba is known which shows immaculate white petals and sepals and a nearly completely white lip.

 

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