Οροβάγχη η αιγυπτιακή
Etymology of Orobanche aegyptiaca
The name of the genus, "Orobanche", derives from Ancient Greek "ὀροβάγχη", from "ὄροβος" [orovos] meaning "vetch" and the verb "ἄγχω" [ancho] meaning "throttle", hence "the vetch throttler", referring to the effect the Orobanche have on their hosts, as they are aggressive root-parasitic weeds exploiting other plants for water, assimilates, and nutrients from their roots. Latin "aegyptiaca" means "Egyptian", as it was initially recorded in Egypt.
The Orobanche genus in Cyprus
It is estimated that around 14 Orobanche taxa (13 species and 1 subspecies) exist in Cyprus.
Orobanche aegyptiaca in Cyprus
Orobanche aegyptiaca is a common Orobanche species in Cyprus, encountered up to an altitude of 1375 metres. It is found in many regions except for the Nicosia city region and the surrounding areas. Orobanche aegyptiaca in Cyprus can be seen flowered any month. The specimen of the pictures was photographed at Kardama locality, at an altitude of approximately 1100 metres.
How to identify Orobanche aegyptiaca
Orobanche aegyptiaca, Orobanche ramosa, and mutelii look very similar. Their identification can be challenging due to their parasitic nature, leading to reduced vegetative parts and significant morphological variability influenced by the host plant. These three species are closely related and are often grouped in the section Tryonichon, sometimes treated under the genus Phelipanche. They are all obligate root parasites lacking chlorophyll. Here is a detailed comparison of their key differences:
Orobanche aegyptiaca (Egyptian Broomrape)
General Appearance and Height
Orobanche aegyptiaca is generally a more robust plant compared to O. ramosa, although its size can also vary with the host. It is often branched, but branching may occur higher up the stem than in O. ramosa, or the plant can occasionally be unbranched. Typical height is 20-30 cm, but it can reach up to 40 cm or be smaller in some cases.
Stem
The stem is usually stouter than that of O. ramosa, often purplish or brownish, and covered with glandular hairs. Branching, if present, may originate from the upper parts of the stem.
Inflorescence
The inflorescence is usually lax, with flowers that are often larger and more widely spaced than in a typical O. ramosa.
Bracts and Bracteoles
Like O. ramosa and O. mutelii, it has one bract and two bracteoles per flower. The bracteoles are typically linear-lanceolate.
Calyx
The calyx is similar in structure to O. ramosa, deeply divided into two segments with pointed teeth, and covered in glandular hairs.
Corolla
A key distinguishing feature is the size of the corolla, which is typically larger than in O. ramosa, measuring 20-35 mm long. The corolla tube is often markedly constricted above the ovary and then widens. The color is usually violet or bluish-purple, often with a paler or yellowish throat, and it is glandular-pubescent. The corolla lobes can be more pointed or acuminate compared to O. ramosa.
Stamens and Anthers
The filaments are inserted lower in the corolla tube than in O. ramosa, usually 2-3 mm above the base. The anthers are often densely hairy, which is a crucial character used to separate it from O. ramosa and O. mutelii.
Stigma
The stigma is typically purplish.
Host Plants
Orobanche aegyptiaca also has a broad host range, similar to O. ramosa, including many vegetables, field crops (like tomato, eggplant, potato, cucurbits, and legumes), and some ornamental plants.
Distribution
It is widespread in the Middle East, Northeast Africa, and extends eastwards to parts of Asia. It is a significant pest in many agricultural areas within its range.
Summary of key differences of Orobache ramosa, aegyptiaca, and mutelii
In summary, while all three species share the characteristic of having branched stems (though less consistently branched in O. aegyptiaca) and flowers with both bracts and bracteoles, the key features for differentiation lie in the corolla length (O. aegyptiaca generally having the longest flowers), the hairiness of the anthers (O. aegyptiaca typically having densely hairy anthers while O. ramosa and O. mutelii have glabrous or sparsely hairy anthers), the insertion point of the stamens in the corolla tube (O. aegyptiaca lower than the other two), and potentially subtle differences in calyx teeth shape and corolla lobe shape. However, due to the inherent variability, especially influenced by the host plant, identification based solely on these morphological characters can be difficult, and some specimens may be hard to assign to a specific species without detailed examination or genetic analysis.