About Veronica catenata Pennell
Veronica catenata Pennell is a perennial, branching herbaceous plant. It produces both erect stems and creeping stems; creeping stems root readily at their nodes. It grows to around 30 cm (12 inches) tall, with stems that range from green to purplish. Stems are usually hairless (glabrous), but may sometimes be hairy. This plant grows on bare ground around ponds and in wetland areas after water recedes, or in open, typically still water. Submerged underwater individuals are brownish and have a very different appearance from terrestrial (above-ground) growing individuals. Its leaves are arranged opposite and decussate, meaning each pair is oriented at right angles to the pair above it, and semi-amplexicaul, meaning leaf bases clasp the stem. Leaf size varies widely: leaves measure 1 to 15 cm (0.4 to 5.9 in) long and 0.3–3 cm (0.1–1.2 in) wide. Aerial leaves are dark green on the upper surface and paler on the underside. They are roughly lanceolate in shape, gradually tapering from a wide base to a pointed tip. Leaf margins are either fully smooth, or slightly serrated near the tip. Inflorescences emerge from leaf bases, most commonly growing in opposite pairs. Each inflorescence can hold up to 50 flowers, each borne on a short pedicel around 5 mm long; pedicels are typically shorter than the bracts located below each flower. Flowers reach up to 10 mm in diameter, and are bisexual. Each flower has 4 pink corolla lobes (petals) marked with deeper pink lines, plus 4 green calyx lobes (sepals). It has 2 stamens with blueish anthers, and 1 style ending in a round stigma. The fruit is a heart-shaped capsule 2–3 mm across, which splits open into 4 valves. The capsule holds numerous pale brown seeds that are flat on one side and rounded on the other. Species similar to Veronica catenata include Veronica anagallis-aquatica, which has purply-blue flowers; Veronica anagalloides, which has elliptic fruits; Veronica × lackschewitzii, which does not produce fruits and often grows into very large plants; and also Veronica scardica and Veronica beccabunga.
