Nomenclature

Species name:

Ophrys melitensis   (Salk.) Deviller-Tersch, Devillers

Author(s):

Hans-Erich Salkowski;
   Germany, 21st Century

Jean Devillers-Terschuren;
   Belgium, 20th Century

Pierre Devillers;
   Belgium, 20th Century

General names:

Maltese Spider Orchid

Maltese name:

Brimba Sewda

Plant Family:

Orchidaceae   (Orchid Family)

Name Derivation:

Ophrys = "Eyebrow", referring to the furry edges of the lips of several species. (Greek);
melitensis = Maltese, concerns the islands of Malta (Latin).

Synonyms:

Ophrys sphegodes ssp. melitensis

Remarks:

An endemic and protected species. -

Botanical Data

Plant Description

Life Cycle:

Perennial

Habitat:

Garigues and arid rocky places.

Frequency:

Scarce

Sources in Malta:

Scarce. Found in several numbers in very few localities around the Maltese Islands, for example Pembroke and Wied Hoxt (Zurrieq).

Plant Height:

5-12cm.

Flowering Time:

Mar - Apr

Poison:

Unlikely to be poisonous.

Like many Ophrys species in Malta, the plant first forms a basal rosette of few, broad, lanceolate leaves. At a later stage the flowering stalk (=scape) grows out through centre of the leaf rosette. About one or two leaves will rise and sheath around the lower half of the fragile flowering scape.

In late winter (typically beginning of March) the flowers open up. They are arranged as a loose spike and the number varies from of 3-12 flowers; depending the habitat of the plants and its age. The flowers are connected to the scape by means of the inferior, cylindrical, untwisted ovary. Each flower has a long, leaf-like, hood-shaped bract which is more or less long till the flower apex.

Each flower has 3 outer perianth segments (=sepals), found perpendicular to each other and arranged as an inverted 'T-shape'. They are broad, 10-12mm long, pale green and often have a central longitudinal darker stripe. There are also 3 internal perianth segments (=petals) arranged as a 'Y-shape' where the lower one is known as the labellum and is highly modified and coloured. The upper two petals have an elongated triangular shape and about 6mm long. These petals vary in colour and they can be pale yellow-green at one extreme to a dark reddish-brown colour at another extreme, or sometimes with reddish-brown blobs. The colour seems to fade away with time. Furthermore, these small petals often have a rugged or undulate margins.

The colour of labellum is dark brown. It has a velvety texture, with longer reddish-brown hairs at its margins, especially the sides. The margin is often curved down. The labellum do not have distinct lobes as many other Ophrys species, however there is a small notch at the tip with a tiny 'tail' at the middle of the notch. The most interesting part of the labellum is undoubtfully the central, shiny violet marking (known also as a speculum). This vary a lot in shape between different specimens but however they can be grouped into 3 basic shapes: 'H' or 'M' shape; horse-shoe or 'n' shape; and two parallel streaks or blobs. The metallic-like specula are highly contrasting with the dark labellum.

The male reproductive organs are two yellow pollinia which are resting over a small platform (called rostellum), wrapped by the sheath-like structures (called theca) and covered by a hood-shaped, erect column or cap. The column have 2 interesting yellow, orange, peach, or red blobs at its sides, more or less where the pollinia reside below. The stigmatic cavity, just below the rostellum is rather large and sticky. The upper half is wax-white and the lower half has the same dark colour of the labellum.

The fertilised ovary will swell up with the developing seeds while the corolla parts shrivel. The ovary eventually becomes the fruit - an oval or cylindrical capsule which is most of the time green, but turns straw colour when it is ripe. It finally splits open longitudinally into 3 parts by which the tiny, powder-like, light seeds can escape out by wind. Seed viability is very low as in many orchids.

Additional Information

Distribution

As mentioned before in this profile, the plant is endemic to the Maltese islands and is not found anywhere else around the world. It is also a scarce plant and is listed as an official protected species according to the Environment Protection Act LN.257 (2003). It must never be picked up! [SM]

Nomenclature

Ophrys melitensis belongs to the Ophrys bertolinii group (the B18 Group) which so far has 11 Ophrys species that share similar morphological characteristics and more importantly that they are all pollinated by bees of the Genus Chalicodoma. The specieas in this B18 group are:
O. bertolonii
O. aurelia
O. benacensis
O. balearica
O. catalaunica
O. saratoi
O. drumana
O. bertoloniiformis
O. explanata
O. flavicans
O. melitensis

Previously this endemic species to the Maltese islands was called O. sphegodes subsp. melitensis but was recentely put in its own taxon of O. melitensis by J.Devillers-Terschuren & P.Devillers in 1992

For long it was included in the O. lunulata group B17, which the general appearance of its flowers suggests, but Hans-Erich Salkowski shortly showed that it is pollinated by Chalicodoma sicula. Since all species of the O. lunulata group are pollinated by bees of the genus Osmia (Hymenopters megachilidae), and all those of the O. bertolonii group B18 by bees of the genus Chalicodoma, it seemed rational to include O. melitensis in the O. bertolonii group, which was done by W. Hahn and H.E. Salkowski, the two Genera of the corresponding pollinator bees giving clear delimitation of the two Ophrys groups. [WWW-143]

Pollination

In Malta, this plant is most of the time pollinated by Chalicodoma sicula subsp. balearica - the Mason bee. [WWW-143] It is found in many valleys. The female collects dust and gravel to form mud and constructs dome-like nest attached to walls or stones. It measures about 14mm long has a dark reddish brown thorax (same colour as the labellum of the plant) and a black abdomen. [360]

Cultivation details

Plants can be grown in a lawn, but the lawn must not be cut until the plants have set seed [200] . Plants prefer a shady position [188] .

Orchids are, in general, shallow-rooting plants of well-drained low-fertility soils. Their symbiotic relationship with a fungus in the soil allows them to obtain sufficient nutrients and be able to compete successfully with other plants. They are very sensitive to the addition of fertilizers or fungicides since these can harm the symbiotic fungus and thus kill the orchid [230] . This symbiotic relationship makes them very difficult to cultivate, though they will sometimes appear uninvited in a garden and will then thrive. Transplanting can damage the relationship and plants might also thrive for a few years and then disappear, suggesting that they might be short-lived perennials [230] .

The flowers resemble a female insect and also emit a scent similar to female pheremones, they are pollinated by a male insect of that species attempting to copulate with the flower [200] . Plants are rather sparingly visited by bees, setting seed only if visited [17] .

Tubers should be planted out whilst they are dormant, this is probably best done in the autumn [200] . They should be planted at least 5cm below soil level [200] .

These cultivation details were given for Ophrys sphegodes, but it can be assumed that these also apply un-differently to the similar specis of O. melitensis [SM]

Propagation

Seed - surface sow, preferably as soon as it is ripe, in the greenhouse and do not allow the compost to dry out. The seed of this species is extremely simple, it has a minute embryo surrounded by a single layer of protective cells. It contains very little food reserves and depends upon a symbiotic relationship with a species of soil-dwelling fungus. The fungal hyphae invade the seed and enter the cells of the embryo. The orchid soon begins to digest the fungal tissue and this acts as a food supply for the plant until it is able to obtain nutrients from decaying material in the soil [200] . It is best to use some of the soil that is growing around established plants in order to introduce the fungus, or to sow the seed around a plant of the same species and allow the seedlings to grow on until they are large enough to move.

This species only rarely forms new offsets and so division is seldom feasible, the following methods can be tried, however [230] .

Division of the tubers as the flowers fade [230] . This species produces a new tuber towards the end of its growing season. If this is removed from the plant as its flowers are fading, the shock to the plant can stimulate new tubers to be formed. The tuber should be treated as being dormant, whilst the remaining plant should be encouraged to continue in growth in order to give it time to produce new tubers [230] .

Division can also be carried out when the plant has a fully developed rosette of leaves but before it comes into flower [230] . The entire new growth is removed from the old tuber from which it has arisen and is potted up, the cut being made towards the bottom of the stem but leaving one or two roots still attached to the old tuber. This can often be done without digging up the plant. The old tuber should develop one or two new growths, whilst the new rosette should continue in growth and flower normally [230] .

These propagation details were given for Ophrys sphegodes, but it can be assumed that these also apply un-differently to the similar specis of O. melitensis [SM]

Personal Observations

The markings of the labellum
O. melitensis, as other related Ophrys species, show a large degree of variability in the speculum (central pale blue marking on the labellum). After taking several photos of flowers of different specimen, I have classified the markings into 3 groups, according to their basic shape.

i) Speculum with an 'H' or 'M' shape.
ii) Speculum with horseshoe or 'n' shape.
iii) Speculum with a pair of blobs or parallel streaks. [SM]

Photo Gallery

Photo of a flower showing mainly the dark brown labellum with a shiny violet blue marking (referred to as speculum) which its shape varies between different specimen.

Photo of a flower which consists of 3 spread-out external tepals (light green) and 3 internal ones with the lower one known as labellum and the upper 2 are slender and in this specimen, pale red.

Photo of a flower against light. Note the hairy margin of the labellum.

Photo of a flower. The upper petals have a rugged or undulated margins and their colour varies from pale red to yellowish green (less common).

Photo of a flower which have two parallel 'i'-shaped markings. The upper internal tepals in this specimen are yellow-green.

Photo of a flower which its markings are simply 2 small blobs. Note also the red dots on the upper internal tepals.

Photo of a flower with 2 large, irregular and parallel streaks.

Photo of another flower at a low angle showing the stigmatic cavity and wavy margin of the labellum. The upper inner tepals of this specimen are yellow-green with a red margin.

Photo of a flower which has a an M-shaped speculum.

Photo of a flower with a speculum having an irregular horse-shoe shape.

Another photo of a flower with a speculum having a horse-shoe shape. Note the small notch at the base of the labellum.

Photo of a young flower with a relatively flat labellum. The outline shape is approximately circular. The speculum is a smooth, horse-shoe shape. The red margin of the labellum is well visible in this specimen.

Photo of a flower with a horse-shoe-shaped marking. Note the tiny appendage (tiny tail) at the notch of the base of the labellum.

Photo of the dark reddish-brown labellum with a rather rounded outline. The shining, violet-blue marking seems to be metallic in sunshine.

Photo of a flower with a thick M-shaped speculum.

Another photo of the Maltese Spider Orchid having a speculum with a rather intersting 'X' shape.

Side view photo of the flower. Note the elevated knob-like structures at the sides of the labellum.

Side view photo of the flower. The margin (especially the sides) of the labellum possess much longer hair from the central part. This photo also shows the detail of the staminal column.

Side view photo of another flower. One of the pollinia is partially detached out. Its glisening base is the viscidum which contains a very sticky substance. Its function is to stick with the body of the pollinator. When this leaves the flower it pulls the entire pollinium and carries it away hopefully to another flower of same species so as to perform pollination.

Another side view photo of flower in situ.

Annotated photo of a flower indicating the main flower parts.

Photo of the stamen column (also called anther cap) which is a small, hood-shaped structure under which resides the pollinia pair, exactly under the lateral red markings. It resembles the head of a lizard!

Photo showing the back side of the labellum and the long hair at the sides.

Photo showing the inflorescence of the plant. It is described as a lax spike, that is non-dense, sessile flowers.

Photo showing the long reddish brown hair present at the outer border of the labellum, especially at the sides.

Photo showing the underside of the labellum. The margin is curved down. The lower photo shows a close up of the hair, about 2mm long.

A compilation of a flower chart which divides flowers in three classes according the basic shape of the speculum: 'H' or 'M' shape; 'ii' shape; or horse-shoe shaped.

Photo of a flower that lacks the blue markings and so have a complete brown labellum.

Scanned image of the inflorescence. The structure attaching the corolla with the scape is the inferior ovary.

Scanned image of the whole flower.

Scanned image of the labellum and stamen column (side view).

Scanned image of the labellum and the stamen column. Note the tiny tail at the base of the labellum.

Scanned and enlarged image of the labellum.

Scanned and annotated image of the outer and inner tepals (excluding the lip petal which is removed to make the scanning possible.).

Scanned and annotated image of the reproductive organs of the flower which mainly consists of the stigmatic cavity and the pair of pollinia above.

Close up photo of the white stigmatic cavity and the stamen column. This photo clearly shows the yellowish pollinia (=stamens) wrapped by the brown coverings called theca. Present at the base of the pollinia are the spherical sticky viscidia (also called bursicles).

Close up photo of the stamen column. In this specimen, the pollinia are absent since they had been carried away by the pollinator. Remaining are the empty coverings.

Close up photo of the yellow pollinium stuck by its viscidium to the pencil tip.

Scanned and enlarged image of the 2-3mm long pollinium.

Photo of few plants in situ. They are either found alone or often in small patches.

Photo of 3 plants close to each other. Probably reproduced from same parent plant.

Photo of a typical plant taken on a garigue in mid March 2006. It consists of few broad-lanceolate leaves arranged as a basal rosette with the younger one(s) more erect and wrapping the scape.

Another photo of the typical low growing plant. When found on deeper and richer soils, the plant grows higher - up to about 12cm long.

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