Πικρίδα η ραγαδιολοειδής

Etymology of Picris rhagadioloides

"Picris" is Ancient Greek from "πικρός'' [pikros] meaning "bitter" in reference to the bitter taste of some species in the genus, which ancient philosophers like Theophrastus noted.

The specific epithet, rhagadioloides, is a compound derived from two elements: "Rhagadiolus" and the suffix "-oides." "Rhagadiolus" is a Latinized form of the Ancient Greek word "ραγάδιον" (raghadion), which means "small slit" or "small crack." This refers specifically to a characteristic feature of the fruits (achenes) of plants in the genus Rhagadiolus. These fruits often have rays or grooves that resemble small slits or cracks. So, when Picris rhagadioloides is named, the -oides suffix still means "resembling," but it's specifically "resembling Rhagadiolus in its characteristic fruit structure or perhaps the appearance of its calyx/flower parts that allude to "slits" or "cracks."

In essence, Picris rhagadioloides means "bitter plant resembling Rhagadiolus (due to its slit-like fruit or calyx features)."

The Picris genus in Cyprus

Three species of the genus Picris are found in Cyprus.

Picris rhagodioloides in Cyprus

The plant is totally absent in the Mesaoria region. It appears between 0-1525 meters altitude. Its flowering period is usually between May and July.

Morphological characteristics of Picris rhagadioloides

Picris rhagadioloides is an annual herbaceous plant, typically ranging from 20 to 80 (occasionally up to 100) cm in height. It's often characterized by its bristly or hairy appearance, which is a key distinguishing feature.

Leaves

The leaves of Picris rhagadioloides exhibit dimorphism (two forms) based on their position on the plant.

Basal leaves are arranged in a rosette at the base of the plant. They are typically narrowly obovate, 5.0-15.0 cm long and 1.3-3.0 (up to 5.0) cm wide, with sinuate-dentate (wavy-toothed) margins and a rounded or obtuse apex. They gradually narrow into a petiole-like base. Both surfaces are thinly hispidulous (covered with stiff, minute hairs).

Cauline leaves (stem leaves) are few and alternate. They are generally smaller, obovate or narrowly oblong, 1.5-8.0 cm long and 0.3-2.0 cm wide. Their margins can be entire or dentate, and they are subacute or acute at the apex, often with short, rounded, projecting auricles (ear-like lobes) at the base where they clasp the stem. Like the basal leaves, they are hispidulous.

Stems

The flowering stems are erect and can be branched or unbranched. They are inconspicuously ribbed and, like the leaves, are hispid. The hairs on the stems are often described as 2-barbed bristles [a "2-barbed bristle" is a stiff hair that has two sharp points like hooks sticking out], sometimes intermixed with shorter indumentum (hair covering).

Flowers

Picris rhagadioloides produces numerous flower heads (capitula) arranged in a paniculiform [paniculate means there is a main stem, and off this main stem, instead of just single flowers, you have smaller branches. And on those smaller branches, you have even more flowers], or corymbose inflorescence [a corymbose inflorescence (or a corymb) is a type of flower cluster where all the flowers end up at roughly the same level, creating a flat-topped or slightly convex appearance]. Each head can contain 30-100 flowers.

The involucre (the cup-like structure enclosing the flowers) is campanulate or broadly campanulate (bell-shaped) during flowering, about 8.0 mm long and 6.0-7.0 (up to 12.0) mm in diameter. The involucre could also be globose to broadly ovoid or urceolate (urn-shaped), especially after the flowering period. The involucral bracts (phyllaries) are in two rows. The outer bracts are narrowly oblong, about 2.0-4.0 mm long and 1.0 mm wide, often tinged purple and hispid. The inner bracts are oblong, about 1.0-1.5 mm wide, acuminate (tapering to a point), and can be purplish or blackish, also hispid. The receptacle (the base where the flowers are attached) is flat to convex and somewhat pitted, without scales. All the flowers are ligulate florets (tongue-shaped with a five-toothed apex) and are typically bright yellow, often with a purple tinge externally. The corolla tube is about 4.0 mm long and pilose (hairy) near the apex, while the ligule is around 9.0 mm long and 2.0 mm wide.

Fruits

The fruits are achenes, which can be homomorphic (uniform) or dimorphic (two forms) within the same plant. They are fusiform (spindle-shaped) in outline, curved, dark brown, and ribbed transversely. Achenes are about 2.5-4.0 mm long and 0.8 mm wide, attenuating into an ill-defined beak. The outer achenes are typically curved and finely wrinkled, ranging from 3.0-4.0 mm long, and have a short, scabridulous (slightly rough) or barbellate (barbed) pappus (a crown of bristles) of about 1.0-2.5 mm. The inner achenes are generally shorter (2.5-3.0 mm long) and possess a longer, plumose (feathery) white pappus, about 5.0-6.0 mm long. The distinct dimorphism in achene and pappus morphology is a key characteristic.

Picris rhagadioloides resembles some Crepis taxa - How to identify it

It is a fact that Picris rhagadioloides can be mistaken for a Crepis species or subspecies. For instance, a robust Crepis rhagadioloides with a paniculate inflorescence resembles Crepis aspera a lot. There is one feature, though, that is really hard to find on Crepis species or subspecies: Crepis rhagadioloides inner and outer bracts have dense, short, stiff hairs that do not appear in the same form on any Crepis species or subspecies. Also, in the case that the involucre has an urceolate shape, it's definitely a Picris.

Key differences between the three Picris species that exist in Cyprus

In Cyprus, we have Picris cyprica, Picris pauciflora, and Picris rhagadioloides. Their key differences are the following:

Achenes

A key distinguishing feature of Picris rhagadioloides is the dimorphic achenes. "Dimorphic achenes" means that the plant produces two distinct types of fruits (achenes) within the same flower head (capitulum). These two types differ in their physical characteristics, particularly their size, surface texture, and most notably, their pappus. Outer Achenes (Peripheral): These achenes are typically found towards the outer edge of the flower head. For P. rhagadioloides, they are described as being curved, slightly longer (3.0-4.0 mm), and having a finely wrinkled surface. Crucially, their outer achenes pappus (the "parachute" of bristles that aids in wind dispersal) is shorter (1.0-2.5 mm) and often described as scabridulous (slightly rough) or barbellate (with small barbs), meaning it's not feathery. This type of pappus suggests more limited dispersal, perhaps allowing these seeds to fall closer to the parent plant. Inner Achenes (Central): These achenes are located towards the center of the flower head. They are generally shorter (2.5-3.0 mm) than the outer achenes. Their most distinctive feature is their pappus, which is longer (5.0-6.0 mm) and plumose (feathery). This feathery pappus is highly effective for wind dispersal, allowing these seeds to travel further away from the parent plant and colonize new areas.

P. cyprica has monomorphic achenes with a consistent plumose pappus. Achenes are fusiform, strongly curved, and generally shorter than the other two, typically 2.0-3.0 mm long. They are glabrous (hairless) or rarely pubescent, brown, and ribbed transversely, with a short beak. The pappus is white and plumose, 5.0-6.0 mm long, and caducous (falling off early). A key difference here is the absence of dimorphic achenes (outer vs. inner)

P. pauciflora achenes are often described as 4.5-5 mm long, dark brown, more or less curved, and strongly transversely muricate (roughened with short, hard points). They have a short beak and a pappus of 2 rows of deciduous hairs.

Hairs/Bristles

Picris rhagadioloides (Hawkweed Oxtongue): This species is particularly distinguished by the presence of 2-barbed bristles. Imagine a straight, stiff hair (a bristle), but along its length, typically near the tip or along the sides, it possesses two minute, outward-pointing projections or hooks. These barbs make the bristles more effective at clinging to surfaces and contribute to the plant's characteristic rough or harsh feel. These 2-barbed bristles are prominently found on the stems and leaves, giving the plant its generally hispid (stiffly hairy) appearance. The involucral bracts (the modified leaves forming the cup-like structure around the flower head) are also hispid, sometimes tinged purple. The consistency and presence of these specific barbed bristles across the plant's vegetative parts are a key indicator.

Picris pauciflora (Smallflower Oxtongue): The hairiness of P. pauciflora presents a different texture and composition. Its leaves and stems typically bear rigid hairs, which are stiff but generally lack the distinct 2-barbed structure seen in P. rhagadioloides. More importantly, the involucral bracts offer distinct hair characteristics. They are often noted to have a mix of short stellate (star-shaped) hairs and longer, rigid hairs. These rigid hairs are particularly concentrated along the median line (the central vein) of the bracts. This combination of hair types, especially the stellate hairs and the specific distribution of rigid hairs on the bracts, is a reliable differentiator. Blackish tips on the outer involucral bracts can also be a visual cue.

Picris cyprica: This species, while it is generally hispidulous (minutely hairy), the bristles on P. cyprica are often described as fulvous (dull orange, brownish-yellow). These fulvous bristles are prominent on both the outer and inner involucral bracts, giving the involucre a distinct color cast that contrasts with the greenish linear bracts themselves. The overall hairiness might be less coarse or dense compared to P. rhagadioloides, and the specific presence of these fulvous bristles on the involucral structures is a valuable identification marker.

Plant Size and Flower Head Number: Overall Growth Form

Picris rhagadioloides (Hawkweed Oxtongue): This is typically a more robust and taller annual species. It commonly reaches heights of 20 to 80 cm, and under favorable conditions, it can even extend up to 100 cm (1 meter). Crucially, its inflorescence is characterized by numerous flower heads (capitula). These heads are borne in a paniculiform (branched cluster) or corymbose (flat-topped) arrangement, giving the overall plant a relatively full and floriferous appearance. The abundance of heads contributes to its common name "Hawkweed Oxtongue," as it can resemble some hawkweeds with their prolific flowering.

Picris pauciflora (Smallflower Oxtongue): As its specific epithet "pauciflora" (from Latin, meaning "few-flowered") suggests, this species generally has a smaller stature and fewer flower heads. It typically grows to a height of 10 to 50 cm, making it often noticeably shorter than P. rhagadioloides. The flower heads (capitula) are fewer in number, and the peduncles (the stalks supporting individual flower heads) are often long, giving the inflorescence a more open and less crowded appearance. This reduced number of flowers and the sometimes longer, more slender peduncles contribute to its more delicate or less robust overall habit compared to P. rhagadioloides.

Picris cyprica: This species typically presents as an annual rosette herb, meaning it forms a flat cluster of leaves at its base before sending up flowering stems. Its height usually ranges from 10 to 50 cm, sometimes reaching up to 70 cm, placing it in a similar height range to P. pauciflora and often shorter than P. rhagadioloides. The number of flower heads can vary, but the emphasis is often on the basal rosette habit. The peduncles (stalks) can be up to 10 cm long and may be slightly swollen at maturity.