Himantoglossum robertianum (Loisel.) P.Delforge, Naturalistes Belges 80: 401 (1999).
Homotypic Names:
Orchis robertiana Loisel., Fl. Gall. 2: 606 (1807).
Barlia robertiana (Loisel.) Greuter, Boissiera 13: 192 (1967).
Heterotypic Synonyms:
Orchis longibracteata Biv., Sicul. Pl. 1: 57 (1806), nom. illeg.
Orchis fragrans Ten., Fl. Napol. 1(Prodr.): LII (1812), nom. illeg.
Orchis foliosa Masson ex Ker Gawl., Bot. Reg. 5: t. 357 (1819), not validly publ.
Orchis longibracteata var. gallica Lindl., Gen. Sp. Orchid. Pl.: 269 (1835).
Orchis longibracteata var. sicula Lindl., Gen. Sp. Orchid. Pl.: 269 (1835).
Aceras longibracteatum Rchb.f. in H.G.L.Reichenbach, Icon. Fl. Germ. Helv. 13-14: 3 (1850).
Aceras longibracteatum var. gallica (Lindl.) Rchb.f. in H.G.L.Reichenbach, Icon. Fl. Germ. Helv. 13-14: 3 (1850).
Aceras longibracteatum var. sicula (Lindl.) Rchb.f. in H.G.L.Reichenbach, Icon. Fl. Germ. Helv. 13-14: 3 (1850).
Barlia longibracteata (Rchb.f.) Parl., Nuov. Gen. Sp. Monocot.: 6 (1858).
Loroglossum longibracteatum (Rchb.f.) Moris ex Ardoino, Fl. Anal. Alpes-Mar.: 351 (1867).
Barlia longibracteata var. gallica (Lindl.) Rouy in G.Rouy & J.Foucaud, Fl. France 13: 182 (1912).
Barlia longibracteata var. sicula (Lindl.) Rouy in G.Rouy & J.Foucaud, Fl. France 13: 182 (1912).
Himantoglossum longibracteatum (Rchb.f.) Schltr., Orchideen Beschreib. Kult. Zücht.: 52 (1914).
Himantoglossum longibracteatum var. gallicum (Lindl.) Schltr. in G.Keller & al., Monogr. Iconogr. Orchid. Eur. 1: 150 (1926).
Himantoglossum longibracteatum var. siculum (Lindl.) Schltr. in G.Keller & al., Monogr. Iconogr. Orchid. Eur. 1: 150 (1926).
Barlia robertiana lusus candida Soó in G.Keller & al., Monogr. Iconogr. Orchid. Eur. 2: 120 (1931).
Himantoglossum robertianum f. candidum (Soó) F.M.Vázquez, Folia Bot. Extremadur. 3: 126 (2009).
Himantoglossum robertianum f. gallicum (Lindl.) F.M.Vázquez, Folia Bot. Extremadur. 3: 127 (2009).
Himantoglossum robertianum f. siculum (Lindl.) F.M.Vázquez, Folia Bot. Extremadur. 3: 126 (2009).
Description:
The bright green leaves are also relatively large; the obtuse ovate to lorate blades can be 10cm wide to 30cm long. They show parallel venation and have a smooth margin which sometimes can have a sinusoidal (wavy) structure. The few-numbered leaves grow directly from the underground tubers as a basal rosette, with the younger ones becoming erect and wrap around the base of the flowering stalk.
The inflorescence is a rather large, cylindrical, dense spike of many flowers (more than 25). The mature spike measures about 15cm or more. Each flower has a labellum of about 2cm (largest amongst the Maltese Orchids).
Each flower has of a rather narrow and long, tapering bract which is longer than the perianth as it measures between 3 or 4cm. The bract is green with purple margins and tip. The Perianth is attached to the flowering stalk by its inferior ovary, usually covered by the bract and the perianth itself.
The perianth consists of 6 tepals or perianth segments; 3 external (=sepals) and 3 internal (=petals). The outer tepals are identical, arranged as an inverted T-shape, 10mm x 6mm in size and are found spreading out. They have a hood-shaped structure, that is curved inwards as concave. They are purple or have many intersecting purple patches with 3 longitudinal green veins. However, from their back, they generally look as maroon.
The inner tepals are arranged as a Y-shape of which the upper two are inconspicuous and arching over the stamenoid column forming a helmet, while the lower one is large, colourful, modified, lip-like structure (called labellum). The labellum has 3 lobes with the median one subdividing into 2 further branches. The undulated margin is maroon or dark brown, which turns to bright purple and then fades to pink or white towards the longitudinal axis. Along the paler parts there are numerous separate irregular purple patches. The flower bears a relatively small (5mm) rounded white spur.
The male reproductive organs consist of 2 pollinia each covered by a brownish pouch-like structure called theca. The pollinia have joined viscidia. The stigma is found as cavity below and behind the stamenoid column.
When the flower is fertilized by a suitable pollinator (eg. Bomblus spp.), the perianth parts shrivel and drop while the inferior ovary enlarges with the developing seeds forming an elongated, ovate fruit capsule which have bulging longitudinal ridges. The bract remains covering partially the ovary. When ripe, the fruit capsule opens up and releases the thousands of tiny and light seeds, which can be dispersed away by wind. Success of seed germination is very low, as in many Orchids.
Name Derivation:
Himantoglossum = Named after the French botanist Jean-Baptiste Barla.
robertianum = Named after another French botanist - Gaspard Nicolas Robert (Robert is the surname)
Habitat:
Usually growing in open ground with alkaline substrate, the Giant Orchid can also appear in open woodland and old olive groves; it likes plenty of sunshine.
Flowering times:
This orchid flowers very early in the year - from the end of February to the beginning of April. The specimens shown here were found in Crete. Other countries were the Giant Orchid occurs include Cyprus, Spain, Portugal and Italy, to name but a few.
Distribution:
Medit.
References:
Pierre Delforge (2005) Orchids of Europe, North Africa and the Middle East; A&C Black; MaltaWildPlants.com by Stephen Mifsud http://www.maltawildplants.com/ORCH/Himantoglossum_robertianum.php