Veronica

Veronica persica

Veronica persica (Common Field Speedwell, Persian Speedwell) - close-up

Above: a flower bud: the blue-white corolla is visible inside the green sepals (calyx). Note the jointed hairs on the sepals which are non-glandular. Two stamens with white filaments (swollen considerably around their mid-section for some unknown purpose) can be seen, each bearing a pair of anther locules (purplish in color) which have split vertically into two valves to release the white pollen. Right: the lower lip has been displaced to the right (whitish color).

Above: trichomes (hairs) were conspicuous on the reddish stems, generally arranged in one wide and one pair of narrow rows but with scattered trichomes between the rows. These possibly serve as an 'assault course' to make it hard for hostile insects to climb the stem without falling off. Trichomes on the petiole (above) and on the leaf (scattered mostly between the veins) are stouter and look like they may be secretory. Short trichomes also occur around the leaf margin (these possible serve to deter those specialist herbivorous insects which target the leaf margins). Lower down the stem the arrangement of the hairs into two clear rows is more apparent.

Above: the stamen filaments anchor at the base of the upper lip. Around their base, extending onto the lower lip, are 'icicle-like' trichomes filled with clear liquid to give them a beautiful glassy appearance (more beautiful when viewed in real life as the photograph is only focused in a narrow plane), some of it already secreted as droplets. This liquid is nectar and the nectary thus consists of specialized secretory trichomes born on the corolla.

Speedwells (Veronica) are not the easiest plants to identify to species level and examination of both flowering and fruiting stages is helpful. However, this plant was distinctive in having each flower born in a leaf (bract) axil on a pedicel (flower stalk) which is much longer than the leaf. The lower petal (lower lip) was also clearly white. Combined with leaf shape and flowering time (March: Veronica persica flowers all year round, though several other species also flower in March) makes this determination likely. To be more sure, however, it is better to examine the fruit capsules if available.

Above and below: From the photographs this is most likely either Veronica persica or Veronica agrestis. The key differences between them are:

• The fruit capsule consists of two compartments which are separated by a wide obtuse angle in Veronica persica and a narrow notch in Veronica agrestis.
• The style on the fruit is long in Veronica persica, short and barely projecting from the notch between the two fruit compartments in Veronica agrestis.
• The sepals and fruit are covered in non-glandular hairs in Veronica persica and gland-tipped in Veronica agrestis.
• The corolla is 8-12 mm wide in Veronica persica, 4-8 mm wide in Veronica agrestis.
• The remaining petal lobes are generally bright blue in Veronica persica, pale blue in Veronica agrestis.

From these photographs it has hard to be certain. However, it looks like Veronica persica and the sepals do appear to be covered by non-glandular hairs and one or two long styles can be seen. Thus, we conclude these are V. persica, which is also the far more common of the two species in this area. Both have the lower petal lip white and both are found on arable and waste land. In both the leaves are borne on short stalks. Veronica persica was introduced to the British Isles from Asia in 1826 but is thought to be native to the Caucasus Mountains and northern Iran. It is self-fertile.

Veronica persica

Now we come on to veronicas with all petals the same color: all blue. Two such examples are Veronica chamaedrys and Veronica polita.

Veronica chamaedrys (Germander Speedwell)

Above and below: Veronica chamaedrys (Germander Speedwell). It occurs naturally in Europe (including Iceland), and northwestern Asia but has been introduced to parts of North America, South America and southern Africa and other parts of Asian (see: http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:811804-1). It is found on banks, in pastures and in woods.

The stems are wiry, decumbent (lying prostrate along the ground without rooting at intervals) rooting only at the base and then ascending. The stem is branched at the base with branches ascending.

The broadly ovate leaves are more-or-less sessile and is equipped with jointed hairs and subcordate at the base (slightly curved inwards at the attachment point) and the tips are obtuse (blunt and rounded). One of the diagnostic features of this species is the two opposite rows of hairs on the stem.

The flowers are borne an lax racemes that originate from leaf axils (raceme: flowers attached by short stalks to the main flowering stem; lax as in widely spaced). The inflorescence stalks (peduncles) appear mostly in opposite pairs and are longer than the leaves. The individual flower stalks (pedicels) are longer than the bracts and longer than the sepals.

Each flower has 4 sepals, which are pointed and narrow, and 4 petals; the sepals covered in jointed hairs, most of which are glandular (gland-tipped). The fruit is a two-part capsule with a wide angled notch between the two compartments at the apex and the style, attached at the base of the notch, is longer than the capsule. The peduncles, pedicels, bracts and calyx are covered by long glandular hairs.

Small bees visiting the flowers of Speedwell reportedly usually land on one of the projecting stamens, clinging to it and potentially picking up some of the sticky pollen. The stamen filament has a flexible base and so droops under the bee's weight, lowering the underside of the bee onto the stigma, to potentially deposit pollen the bee may be carrying from an earlier visit to another flower.

Veronica montana (Wood Speedwell)

Wood Speedwell is native to much of Europe and parts of northern Africa (see: http://powo.science.kew.org/taxon/812334-1). It is found in woods and moist hedge-banks. It is similar to Veronic chamaedrys, with wiry decumbent stems rooting close to the base but stems hairy all around their circumference. the flowers are said to be all white with red-lilac veins in some sources, lilac in others. The stems are more decumbent than in Veronica chamaedrys.

The leaves are always stalked and covered in short jointed hairs (shorter than those in Veronica chamaedrys). The plant is a lighter green than Veronica chamaedrys and the 4 sepals are much broader and covered in jointed hairs, which are usually non-glandular. The style is again longer than the fruit capsule but the capsule is a different shape with a wide obtuse angle separating the two compartments at both the base and apex.

Based on recent molecular evidence Veronica has been moved from Scrophulariaceae to the family Plantaginaceae (the Plantain family). Scrophulariaceae was something of a dumping ground and was polyphyletic (containing diverse groups with different evolutionary origins). Most modern taxonomists work to create a classification scheme that reflects evolutionary origins, which is good, but it remains to be seen whether such a scheme will be as useful to the field botanist, many of whom use older classification schemes. Updating classification schemes in herbaria is also very labor-intensive and many herbaria use older classification schemes.

Above: Speedwell ( Veronica) - this looks like Veronica chamaedrys (Germander speedwell)

Veronica officinalis (Heath Speedwell)

Veronica serpillifolia (Thyme-leaved Speedwell)