More Lamiaceae
Stachys sylvatica (Hedge Woundwort)
Above: Hedge Woundwort (Stachys sylvatica).
Above: Stachys sylvatica - unfurling flowers up close.
Teucrium scorodonia (Wood Sage)
Above: The Wood Sage, or Woodland Germander, Teucrium scorodonia is a member of the lamiate family and is a germander. (Cromer's Wood, Kent, UK). Unlike true sages it has little aroma. Although up to 2 feet (24'' or 60 cm) in height, the Wood Sage can be easily overlooked since its flower spikes bear tiny yellow-green flowers. However, close inspection reveals the extraordinary beauty of each tiny flower. Like lamiates in general the flowers are zygomorphic (with bilateral symmetry and a definite top and bottom). The flowers are functionally protandrous, opening first as functionally male, with the 4 stamens hanging below the non-functional female style and stigmas. Later, the depleted stamens bend upwards and the style brings the stigmas down to contact any potentially pollen-carrying insect. The pale yellow-white lower lip or labellum also appears to undergo movements as the flower matures. The oldest flowers are at the bottom of the spike and are withering as the topmost are still in bud. The fact that the corolla (petal tube) of Wood Sage has no (or a very reduced0 upper lip means that these changes in stamen and stigma positions can be readily seen in this species, as in the photo above. Similar movements are characteristic of the lamiates. Bugle, Ajuga reptans, also has a much reduced upper lip and similar changes are also easily observe din this species.
Looking at a spike of developing Wood Sage flowers, it can be seen that the uppermost flowers are functionally male, with ripe anthers held into the correct position to contact a pollinator. Further down the spike are older flowers in which the shriveled anthers are first moved out of the way by a spreading outwards of the stamen filaments and then the forked tongue-like stigma-style protrudes into a receptive position to receive pollen from a pollinator.
The oval leaves of Wood Sage are typically 3 to 7 cm in length with cordate bases. (Cordate: having the midline of the base indented as in a cartoon heart). Antunes and Sevinate-Pinto (1991, Flora 185: 65-70) studied the trichomes (hairs) on the leaves of Teucrium scorodonia which consist of at least two types of glandular hairs and non-glandular hairs. The type 1 glandular hairs consist of a basal cell, a short stalk cell and a head of 4 secretory cells, whilst type 2 secretory cells consist of a basal cell, a longer stalk cell and a glandular head of two glandular cells. Similar glandular hairs occur in many lamiates and may secrete essential oil, though the functions of their secretions are not always clear.
The type 1 secretory cells secrete a mucilaginous or oily secretion. This secretion accumulate within a space between the outer and inner cell wall layers and evidence suggests that eventually the top of the cell wall detaches along a predetermined ring of weakness, to release the secretion. Since these glands are densest on the immature leaf, spreading apart as the leaf grows and expands, Antunes and Sevinate-Pinto have suggested that the secretion serves as lubricant to reduce friction when the leaves unfurl from the bud and expand, as has been shown in another lamiate, Thyme (Thymus) by Modonesi, Serrato-Valenti and Bruni (1984, Flora 175: 211-219). Glandular secretions in some plants have been shown to have anti-microbial or anti-insect properties and may serve to protect young leaves and leaves in the bud. The functions of hairs and glands in flowering plants are extremely diverse and often poorly understood. However, such glands provide us with essential oils of interest to medicine and the aromatics industry.
Wood Sage grows on dry soils that are not too high in calcium, in woods, dunes, grasslands and heathlands and flowers throughout summer.
Wood Sage is a perennial and native to Western Europe and Tunisia. Due to its bitter taste the whole plant can act as a substitute for hop flowers, however, it does contain compounds that are toxic to the liver. The Teucrium (Germander) genus is of medical research interest due to the powerful antioxidants they contain.
Above: Wood Sage flowers being visited by beetles (Coleoptera).
Clinopodium vulgare ( = Calamintha clinopodium, Wild Basil)
Note that this basil is not a very close relative of culinary basil (Ocimum basilicum which is in the same family but a different genus).
The leaves of Clinopodium vulgare are essentially ovate but can be wider towards the base and deltoid or narrower and lanceolate-ovate.
The flowers occur in a terminal flower head and lower whorls of flowers beneath. These whorls are actually false whorls or verticillasters since the flowers do not actually develop at the same level along the stem and so are not true whorls (verticils). Each verticillaster consists of a pair of condensed almost stalkless cymes: condensed meaning that the inetrnodes are greatly shortened so the flowers all appear to be more-or-less borne at the same level. (A cyme is an inflorescence in which each axis, the main axis and side-branches, ends in a flower with the flower atop the main axis being the oldest and generally opening first). This inflorescence type is typical of many lamiates. The bracts (as in the bracteoles or secondary bracts, subtending each flower as opposed to the primary bracts subtending the inflorescence stalk (peduncle)) are setaceous (bristle-like) and each cyme bears numeorous such bristles. Each flower is borne on a short pedicel. The five sepals are fused into a reddish caylx tube with 5 pointed teeth and coated with hairs.
Wild Basil is a perennial that occurs naturally throughout most of Europe, north Africa and the northern USA and has been introduced, for example, in Australia, Brazil and Ireland. In Britain it occurs naturally in open woods and can be found in hedges and similar habitats.
The perennial rootstock is woody, 'shortly creeping' and branched and puts out stolons in autumn as slender ascending stems bearing leaves towards the apex. The unbranched stems are more-or-less erect and reach 30 to 90 cm in height.
The fruit of lamiates consists of a compound nut, that is a cluster of small nutlets (nucules), which are just beginning to develop inside the calyx tube of some of the finished flowers in the photo above. Though green when young, the nutlets turn dark-brown when ripe.
Origanum vulgare
(Wild Marjoram, Winterseet)
Above: Wild Marjoram, Origanum vulgare, growing on calcareous soil. Habitat: grasslands, scrub, hedgebanks, on calcareous soils. Note the characteristic protruding stamens and the purple tips of the bracts beneath each flower. (Apparently, however, the stamens do not protrude in all specimens). The leaves are borne on short petioles. Origanum vulgare is a perennial with a woody rootstock which is shortly creeping, and so may put out a tuft of stems and puts out slender ascending stolons, similar to those of Clinopodium vulgare, with leafs towards the apex.
The inflorescence of Common Marjorum consists of a cluster of spikes, each at the end of an axisd (both the main stem and branches) grouped into a corymbose-panicle. A spike is an inflorescence consisting of stalkless flowers borne on a central axis; a panicle is a compound raceme, a raceme being similar to a spike but with each flower borne on a definite stalk. In this case the inflorescence consists of a central axis bearing branches, in which each branch bears flowers with no noticeable stalks, so a compound spike would appear to be a better description. 'Corymbose' means resembling a corymb. A corymb is an inflorescence in which the lower flowers have longer stalks, such that all the flowers are borne up to more-or-less the same height. In this case we have a compound inflorescence, but the stalks of the lower/outer spikes are longer so all the spikes are brought to a similar height. Describing branching patterns in inflorescences is often no simple matter! The fruit are brown nucules.
Wild Marjorum occurs in open woodlands but also on grassy banks, roadsides and in waste places and has a preference for chalky soil. The one pictured above was growing on a chalk bank in a calcareous grassland habitat. It is native to much of Eurasia and parts of north Africa but has also been introduced into some regions, such as parts of North America. The leaves contain translucent vesicles of aromatic red oil that has been used for its medicinal properties.
Glechoma hederacea (Ground Ivy)
Ground Ivy is a bitter aromatic herb that was formerly used in beer and infused as a tea. It is a native to Eurasia but has introduced elsewhere and is invasive in North America. In Britain it occurs in woods, hedge-banks and in damp shaded habitats.
The stem is procumbent, branched and rooting. The flowering stems are mostly ascending or erect and up to 30 cm in height. The plant is perennial.
The leaves are stalked, more-or-less reniform (kidney-shaped) and cordate (the base of the leaf-blade margin is concave inwards like the top of a cartoon heart). The leaf margins are crenate or crenate-serrate.
The flowers are arranged in verticillasters (false-whorls) of 2 to 8 flowers each. The fruit are dark brown nucules. The bracts (primary bracts beneath verticillasters) are similar to the stem leaves; the secondary bracts or bracteoles (beneath each flower) are shorter than the pedicels (flower-stalks).
Article created/updated: 19 April 2020 /
July 2020