Verbena officinalis L.

Code

VEBOF

Growth form

Broadleaf

Biological cycle

Perennial

Habitat

Terrestrial

Global description
 
Verbenna officinalis is an herbaceous perennial plant, spread first then erect, with quadrangular stem, simple, opposite, decussate, sub sessile, narrowly elliptic and strongly serrated-lobed leaves. The inflorescence consists of solitary spikes or grouped in linear terminal panicles, consisting of numerous small, tubulate, pale lilac flowers.
 
General habit
 
Verbena officinalis is a perennial herb, quickly branched, reaching up to 1 m in height.
 
Underground system
 
The root system consists of a taproot.
 
Stem
 
The stem is quadrangular, solid, erect or decumbent at the base and then erect, slightly grooved on two opposite faces, glabrous or slightly scabrous particularly on the angles. It branches out quickly.
 
Leaf
 
The leaves are simple, opposite, decussate. They are short-stalked to sessile, especially at the top of the plant. The lamina is narrowly oval, elliptical or oblong, 2.5 to 8.5 cm long and 0.75 to 5 cm wide. The base is extensively attenuated into a false petiole or a very short petiole, the apex is more or less sharp. The margin is strongly lobed to serrated (pinnatifid to pinnatipartite). Both sides are glabrous to finely pubescent with very short hairs. The upper leaves are smaller, narrower, sessile and with slightly serrated margin.
 
Inflorescence
 
The inflorescences are slender spikes, elongated, loose, consisting of numerous flowers. They are solitary or grouped by 3 or in terminal panicles. They are 3 to 15 (25) cm long.
 
Flower
 
The flower is subtended by a bract shorter than the calyx, oval, 2 mm long and 1 mm wide, acute, ciliated. The calyx in tube is 2 to 3 mm long, with dense glandular pubescence, ending with tines, 0.5 mm acute. The corolla is pale lilac to pale blue in colour. It consists of a long tube, 3 to 4 mm, cylindrical. It flares out at the top into a lamina, 3 to 5 mm in diameter with five tines among which 3 are large of 2 mm long and 1.7 mm wide and 2 short of 1 mm long and 1.5 mm wide.
 
Fruit
 
The fruit is a tetrakene which separates at maturity in 4 nutlets (achene with lignified pericarp) oblong, linear, trigonal, 1.8 to 2 mm long and 0.5 to 0.7 mm in diameter, reddish brown, shiny, rough, reticulate.

Verbena officinalis is a perennial species. It multiplies mainly by seeds, and also by cuttings or division of the root system.

Verbena officinalis can be confused with V. brasiliensis, V. bonariensis and V. rigida.

Comparison table for species for genus Verbena

	Insertion of leaf	Base of lamina	Margin of lamina	Spike		Tube of corolla	Bracts
V. officinalis	stalked	wedged	pinnatifid	In panicule	elongated L > 5 cm	L - 2 x calyx	L < calyx
V. brasiliensis			Finely serrated		short and compact L < 5 cm
V. bonariensis	sessile	Cordate to auriculate		in corymbose			L 1 to 1,5 x calyx
V. rigida						L 2 to 3 x calyx	L 1,5 to 2 x calyx

Mauritius: Verbena officinalis is a naturalized species, common weed in sugarcane fields and fallow at all altitudes.
Reunion: Absent.
Rodrigues: Species naturalized.

Mauritius: Verbena officinalis is a common weed in sugar cane fields at all altitudes.
Reunion: Absent.

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Verbena%2520officinalis