Annual plant: lifecycle, cultivation, and examples Annual plant An annual plant completes its lifecycle in a single growing season. This article explains definitions, traits, cultivation practices, common examples, and how annuals differ from b…
Annual Tree Mallow (Lavatera) — overview, identification, and garden uses Annual Tree Mallow Annual tree mallow is a fast-growing, short-lived Lavatera commonly grown for large hibiscus-like flowers; easy to cultivate, attracts pollinators, and is useful in cottage and inf…
Anthurium: flamingo flowers and the tropical arum genus Anthurium Anthurium is a large Neotropical genus in the Araceae family, known for its spathe-and-spadix flowers and popular cultivated varieties used as houseplants and cut flowers.
Aphid: biology, impact on plants, control, and notable facts Aphid Aphids are small sap‑feeding insects (over 4,000 species) that damage plants directly and by spreading viruses. This article covers their biology, impacts, natural enemies, control…
Apiaceae (Umbellifers): the carrot family and its significance Apiaceae Apiaceae, or umbellifers, is a widespread family of aromatic, often hollow-stemmed flowering plants that includes many culinary herbs, vegetables and a few toxic species noted for…
Apiales: the order of umbels and related flowering plants Apiales Apiales is an order of flowering plants within the asterid clade, including the carrot and ginseng families. It contains many aromatic herbs and woody plants important in cuisine,…
Apocynaceae — the dogbane and oleander family Apocynaceae Apocynaceae is a diverse family of flowering plants (trees, shrubs, herbs, lianas) known for milky sap, complex flowers and both toxic and medicinal species; circumscription and us…
Apocynum cannabinum (Indian hemp) Apocynum cannabinum Apocynum cannabinum, commonly called Indian hemp or dogbane, is a North American perennial valued historically for its strong bast fiber and noted for its distinctive flowers, seed…
Apple (Malus): fruit, tree, cultivation, uses, and global importance Apple Overview of the apple: botanical identity, characteristics, origins, cultivation methods, pests and diseases, uses in food and industry, and its cultural and economic significance…
Apricot Apricot (Prunus armeniaca) is a small stone fruit prized fresh or dried, native to Central Asia and cultivated worldwide for its flavor, nutrition and culinary uses.
Aquatic plant: types, adaptations, roles and uses Aquatic plant A concise overview of aquatic plants: what they are, common types and adaptations, ecological roles, uses in gardens and aquaria, and important distinctions with examples like wate…
Aquilegia (columbine): spurred perennial flowers of the Northern Hemisphere Aquilegia Aquilegia, commonly called columbine or granny's bonnet, is a genus of about 60–70 spurred perennial plants valued in gardens and studied for their floral diversity and pollination…
Arabidopsis thaliana: a model plant for genetics and molecular biology Arabidopsis thaliana Arabidopsis thaliana is a small mustard-family plant widely used as a laboratory model. Its small genome, rapid life cycle and genetic tools have made it central to plant biology a…
Araceae (Arum family): characteristics, ecology, uses, and notable genera Araceae Araceae, the aroid or arum family of monocot flowering plants, are defined by a spadix inflorescence with a spathe. This article covers their traits, distribution, ecology, uses, a…
Araliaceae: the ivy family — diversity, features, and uses Araliaceae Araliaceae is a family of mainly woody flowering plants including ivies, ginsengs and scheffleras, known for compound leaves and clusters of small flowers; widely used ornamentally…
Araucaria: ancient conifer genus and its natural history Araucaria Araucaria is a small genus of evergreen conifer trees with a Mesozoic origin; species occur in the southern Pacific, South America and Brazil and include notable trees like the mon…
Araucaria heterophylla (Norfolk Island Pine) Araucaria heterophylla A conifer native to Norfolk Island, Araucaria heterophylla is an ornamental tree with a distinctive layered habit. It is valued in cultivation worldwide and is considered vulnerabl…
Arboriculture: The Science and Practice of Caring for Trees and Shrubs Arboriculture Arboriculture is the professional study and practice of planting, pruning, diagnosing and maintaining individual trees and shrubs to promote health, safety and landscape value in u…
Archaefructus: an early aquatic flowering-plant genus Archaefructus Archaefructus is an extinct genus of herbaceous aquatic seed plants from the Early Cretaceous Yixian Formation; its unusual reproductive architecture has shaped debates about early…
Arctic willow (Salix arctica) Arctic willow A compact, cold-adapted willow of the tundra. Salix arctica is a dwarf woody plant with hairy leaves and low, creeping growth, important ecologically and used historically for medi…
Argemone (prickly poppy): description, distribution, uses and risks Argemone Argemone, commonly called prickly poppy, is a genus of spiny, poppy-like plants used ornamentally and in folk medicine; several species are weedy and contain toxic alkaloids linked…
Aristolochia — birthworts and pipevines (Aristolochiaceae) Aristolochia Aristolochia is a genus of roughly 500 species of herbs, vines and shrubs called birthworts or pipevines. Notable for tubular flowers, larval host relationships, medicinal history…
Aristolochiaceae (Birthwort or Pipevine Family) Aristolochiaceae Aristolochiaceae is a small family of flowering plants (about seven genera, ~400 species) in the order Piperales, known for pipe-shaped flowers, specialized pollination, and toxic…
Artemisia (genus of flowering plants) Artemisia (genus) Artemisia is a diverse genus of aromatic herbs and shrubs in the daisy family Asteraceae, widely distributed across temperate regions of the Northern Hemisphere and notable for med…
Artemisia absinthium (wormwood): description, history and uses Artemisia absinthium Artemisia absinthium, or wormwood, is a silvery perennial herb used historically in bitters, medicines and absinthe. This article covers its appearance, chemistry, cultivation, use…
Artemisia annua (sweet wormwood): description, uses, and significance Artemisia annua Artemisia annua, or sweet wormwood, is an annual herb native to temperate Asia. It is the botanical source of artemisinin, a key antimalarial compound, and has uses in traditional…
Artichoke (Cynara scolymus): description, cultivation, culinary uses, and history Artichoke Artichoke (Cynara scolymus) is a perennial thistle of the daisy family grown for its edible immature flower buds. This article explains its form, origins, cultivation, culinary use…
Asclepiadoideae — the milkweed subfamily Asclepiadoideae Asclepiadoideae is the milkweed subfamily of Apocynaceae: a diverse group of herbs, vines, succulents and shrubs known for milky latex, intricate flowers with pollinia, and ecologi…
Asclepias amplexicaulis — clasping (sand) milkweed: overview, habitat, and ecology Asclepias amplexicaulis Asclepias amplexicaulis, the clasping or sand milkweed, is a spring‑flowering North American milkweed with stem‑clasping leaves, clustered flowers and toxic milky sap; important to…
Asclepias asperula (antelope horns) Asclepias asperula A North American milkweed species known as antelope horns or green‑flowered milkweed; spring‑blooming, pollinator‑friendly, and adapted to sandy or rocky soils in the southwestern…
Asclepias californica — California (round-hooded) milkweed Asclepias californica Asclepias californica, the California or round-hooded milkweed, is a native West Coast perennial adapted to dry slopes; noted for hooded pink flowers, milky sap, pollinia pollinati…
Asclepias curassavica — scarlet milkweed (Mexican butterfly weed) Asclepias curassavica A tropical milkweed native to Central and South America, known for red-orange flower clusters, popularity with butterflies, widespread naturalization, and implications for cultivat…
Curtiss's milkweed (Asclepias curtissii) Asclepias curtissii Asclepias curtissii, or Curtiss's milkweed, is a Florida-native milkweed in the subfamily Asclepiadoideae noted for its clustered flowers, role for pollinators, and restricted coas…
Asclepias eriocarpa — woollypod (Indian) milkweed Asclepias eriocarpa Asclepias eriocarpa, the woollypod or Indian milkweed, is a perennial milkweed of the western United States; adapted to dry soils, with clustered flowers, woolly seed pods and ecol…
Asclepias erosa — desert milkweed Asclepias erosa Asclepias erosa, the desert milkweed, is a perennial milkweed native to the southwestern United States. It produces clusters of pale yellow flowers in late spring and grows on dry…
Asclepias fascicularis — Narrowleaf (Mexican) Milkweed Asclepias fascicularis Concise overview of Asclepias fascicularis, a western North American narrow-leaved milkweed: appearance, habitat, ecological role for pollinators (including monarchs), cultivation,…
Asclepias humistrata — sandhill (pinewoods) milkweed Asclepias humistrata A southeastern U.S. perennial milkweed adapted to dry, sandy pinewoods. Noted for rose-pink umbels, drought tolerance, importance to pollinators (including monarchs), and use in re…
Asclepias nivea — Caribbean milkweed Asclepias nivea Asclepias nivea, the Caribbean milkweed, is a milkweed species in the subfamily Asclepiadoideae native to Puerto Rico and the U.S. Virgin Islands; noted for white flowers, milky sa…
Asclepias physocarpa — swan plant (balloon milkweed) Asclepias physocarpa A milkweed species noted for its inflated, papery seed pods, ornamental use, and value to butterflies; native to parts of Africa and widely naturalized in warm regions including Ha…
Asclepias purpurascens (Purple Milkweed) Asclepias purpurascens Asclepias purpurascens, the purple milkweed, is a North American perennial milkweed with pink‑purple umbels. It grows in prairies and savannas, supports pollinators, and prefers su…
Asclepias syriaca — common milkweed Asclepias syriaca Asclepias syriaca, the common milkweed, is a North American native perennial known for its clusters of pinkish flowers, milky sap, seed floss, and importance to pollinators—especia…
Asclepias tuberosa (butterfly weed) Asclepias tuberosa Asclepias tuberosa, or butterfly weed, is a perennial North American milkweed with bright orange to yellow blooms that support pollinators and are used in gardens; prefers sunny, w…
Ash tree (Fraxinus): description, uses, distribution and threats Ash tree Ash (genus Fraxinus) are temperate trees in the olive family, known for pinnate leaves, winged seeds called keys, versatile hardwood, cultural roles, and modern threats such as pes…
Asparagaceae: the asparagus family of flowering plants Asparagaceae Asparagaceae is a diverse family of monocot flowering plants (order Asparagales) that includes asparagus, agaves and many ornamentals; its circumscription was revised using molecul…
Asparagales — order of monocot flowering plants Asparagales Asparagales is a large order of monocot flowering plants including asparagus, orchids, irises and many ornamentals. Families and limits have shifted with molecular studies; members…
Asparagus: botany, cultivation, uses, and notable facts Asparagus Asparagus is a diverse genus of perennial flowering plants best known for the edible Asparagus officinalis. This article covers its biology, cultivation, culinary uses, history and…
Asparagus officinalis (garden asparagus) Asparagus officinalis Perennial flowering plant cultivated for its tender spring shoots. Native to Europe, northern Africa and western Asia, valued in cooking, horticulture and nutrition and known for g…
Aspen (Populus): description, biology, uses and notable facts Aspen Aspens are fast-growing Populus trees known for their trembling leaves, clonal colonies and important ecological and cultural roles across northern temperate regions.
