Hemlock is also known as Devil's porridge, beaver Poison, musquash root, cowbane or poison parsley. Hemlock is a very poisonous plant that has been used for centuries for assassinations and executions. It is extremely toxic to humans and animals, and eating any amount can cause death. It is most toxic when it is fresh.
Hibiscuses are tropical shrubs with big, showy flowers that only last a day. Their flowers are usually shades of red, pink or yellow. They can live in very hot, dry areas but do not tolerate frost. Some kinds of hibiscus have flowers that can be eaten or used to make tea or jam, other kinds of hibiscus are used to make paper.
European holly is a flowering, evergreen small tree or shrub with glossy, prickly leaves and red berries. The berries are not good to eat, and will make you feel sick and vomit. Lots of birds and animals can eat them though. Holly is associated with Christmas.
Hops is a plant grown for its flowers, which are added to beer to make it bitter. The hop plant is a climbing plant that is usually grown up poles or on strings in a field. Hop plants can grow very fast, and climb by wrapping themselves clockwise around anything they bump into. It grows vigorously in spring but dies back to a frost-hardy bulb in autumn.
Hydrangeas are a flowering plant from Southeast Asia. They grow big bundles of flowers and look very nice put in a vase. Some types of hydrangea change colour depending on how acid the soil is. They grow blue flowers in acidic soil, white or pale cream flowers in neutral soil and pink or purple flowers in alkaline soils.