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Plantaginaceae & Scrophulariaceae

This video is a bit different to previous Five-minute families ones, because today we are looking at two families together: the Plantaginaceae, or plantain family, and the Scrophulariaceae, or figwort family. This is because of the taxonomic history and characteristics of these 2 families. In the past, the Plantaginaceae was a relatively small family and the Scrophulariaceae much larger. The species in both each had a distinctive set of physical features. However, in recent years the use of molecular techniques that look at similarities and differences in the DNA of plants has revealed that many of the species in the Scrophulariaceae were better placed in other families. Quite a lot of them were reclassified into the Plantaginaceae. So, the Plantaginaceae now contains around 1900 species, and The Scrophulariaceae around 1880 species. Because these species were reclassified based on their DNA, rather than their physical appearance, these 2 families have a lot of species with the same set of features. Just to make things a bit more complicated, there are a few other families that some former Scrophulariaceae species have been moved into as well, like the Orobanchaceae, or broomrape family. The Plantaginaceae and Scrophulariaceae are cosmopolitan in distribution, with species from these families found across the world, with many in temperate areas. Most of these species are herbaceous or shrubby, with a few trees. There are annuals, biennials and perennials. The Plantaginaceae and Scrophulariaceae contain many ornamental species, like Veronica, speedwells and hebes, Antirrhinum majus, snapdragon, and Penstemon, beardtongues, in the Plantaginaceae, and Buddleja, butterfly bushes, and Nemesia in the Scrophulariaceae. Some have been used medicinally, like Digitalis, foxgloves, in the Plantaginaceae and Verbascum thapsis, greater mullein, in the Scrophulariaceae. Mullein is also an invasive weed in some countries in has been introduced to. In the UK, species in these families are herbaceous or shrubby and include annuals, biennials and perennials. Wild UK Plantaginaceae include Digitalis purpurea, foxglove, Veronica such as V. chamaedrys, germander speedwell and V. montana, wood speedwell, Cymbalaria muralis, ivy-leaved toadflax, Linaria vulgaris, common toadflax and, of course, Plantago, the plantains, like Plantago major, greater plantain, and P. lanceolata, ribwort plantain. Wild Scrophulariaceae include Scrophularia nodosa, common figwort, and Verbascum thapsus. Plants in these families mostly have irregular flowers, meaning they are only symmetrical along one axis or plane. The Veronica species have flowers that are closer to being regular in shape, symmetrical in more than one plane. The Plantago species have regular flowers, but this is not easy to see as they are tiny and grow in dense spikes. The flowers have 4 or 5 fused sepals and 4 or 5 petals, also joined into a tube. The petals in many species are modified to form and upper and lower lip, often with 2 lobes on the upper lip and 3 lobes on the lower lip, such as can be seen in this Linaria vulgaris. Some also have a spur on their flowers, which holds nectar. The aquatic species in Hippuris and Callitriche, mare’s-tail and water-starworts, have no sepals or petals. The flowers have 4 or 5 stamens; Veronica have only 2. Often there is a pair of longer stamens and a pair of shorter stamens. The ovaries of the flowers are superior, attached above the rest of the floral parts, and consist of 2 lobes fused together. There is one stigma per flower and this is attached on top of the fused ovaries, unlike in the Lamiaceae, where the stigma emerges from between the 4 lobes of the ovary. The flowers are mostly pollinated by insects and they form 2-celled capsule fruits. The capsules break open to disperse the seeds. The leaves in these 2 families vary widely, ranging from simple to compound and entire to divided, mostly simple. In some species they are arranged alternately on the stems, and in some they are arranged oppositely on the stems. In Hippuris they are whorled. However, none of them have stipules. Because of the variability in features between species, it’s not easy to summarise identifying characters for the Plantaginaceae and Scrophulariaceae, but here goes. The flowers have 4 or 5 sepals and 4 or 5 petals, are often 2-lipped and the stamens are often in pairs of different lengths. The fruits are capsules. The leaves vary in shape and arrangement. See if you can find these species when you’re out and about: In the Plantaginaceae: • Plantago lanceolata, ribwort plantain... • Digitalis purpurea, foxglove... • Veronica chamaedrys... And in the Scrophulariaceae: • Buddleja davidii, butterfly bush, a common non-native garden escape with two-toned leaves and big spikes of purple flowers • Verbascum thapsus, greater mullein, with a rosette of large, woolly leaves and large yellow flowers in spikes [Botanical names should be typed in italics]