Flowers that start with A range from garden mainstays to one of the most poisonous plants in Europe. Asters, azaleas, alliums, alstroemeria, amaryllis and snapdragons are all here — and so is aconite, which has killed people who mistook its root for horseradish.
This guide covers 28 flowers beginning with A, with botanical names, plant type, bloom season and what makes each one distinctive. Toxic species are flagged clearly.
Flowers Starting With A: Quick Reference
| Flower | Botanical Name | Type | Blooms | Notes |
|---|---|---|---|---|
| Abelia | Abelia spp. | Shrub | Summer–autumn | Long flowering; scented tubular blooms |
| Acanthus | Acanthus mollis | Perennial | Early summer | Bear’s breeches; the leaf on Corinthian columns |
| Achillea | Achillea millefolium | Perennial | Summer | Yarrow; flat plates of tiny flowers, very drought tough |
| Aconite | Aconitum spp. | Perennial | Late summer–autumn | Monkshood — among the deadliest garden plants |
| African Daisy | Osteospermum spp. | Tender perennial | Spring–autumn | Closes at night and in dull weather |
| African Lily | Agapanthus spp. | Perennial | Summer | Globes of blue or white; flowers best pot-bound |
| Ageratum | Ageratum houstonianum | Annual | Summer–frost | Floss flower; fluffy blue-mauve heads |
| Alchemilla | Alchemilla mollis | Perennial | Early summer | Lady’s mantle; leaves hold water as beads |
| Allium | Allium spp. | Bulb | Late spring–summer | Ornamental onion; spherical flower heads |
| Aloe | Aloe spp. | Succulent | Winter–spring | Tubular red or orange spikes; bird-pollinated |
| Alstroemeria | Alstroemeria spp. | Perennial | Summer | Peruvian lily; exceptional vase life |
| Alyssum | Lobularia maritima | Annual | Spring–autumn | Honey-scented carpet; excellent for edging |
| Amaryllis | Hippeastrum spp. | Bulb | Winter indoors | Huge trumpets — bulbs toxic |
| Anemone | Anemone spp. | Perennial / tuber | Spring or autumn | Windflower; spring and autumn types differ greatly |
| Angel’s Trumpet | Brugmansia spp. | Shrub | Summer–autumn | Huge pendant trumpets — severely toxic |
| Angelonia | Angelonia angustifolia | Tender perennial | Summer–frost | Summer snapdragon; thrives in heat |
| Anthericum | Anthericum liliago | Perennial | Late spring | St Bernard’s lily; white starry spikes |
| Anthurium | Anthurium spp. | Tender perennial | Year-round | Glossy spathe with a central spadix |
| Antirrhinum | Antirrhinum majus | Annual / short perennial | Summer | Snapdragon; hinged flowers open when squeezed |
| Arabis | Arabis spp. | Perennial | Spring | Rock cress; mat-forming for walls and rockeries |
| Armeria | Armeria maritima | Perennial | Late spring–summer | Sea thrift; tolerates salt and thin soil |
| Arum Lily | Zantedeschia aethiopica | Rhizome | Spring–summer | Calla lily — sap irritates, all parts toxic |
| Aster | Symphyotrichum / Aster | Perennial | Late summer–autumn | Key late nectar source before winter |
| Astilbe | Astilbe spp. | Perennial | Summer | Feathery plumes; needs reliably moist shade |
| Aubrieta | Aubrieta deltoidea | Perennial | Spring | Cascades over walls in purple sheets |
| Azalea | Rhododendron spp. | Shrub | Spring | Acid soil required — all parts toxic |
| Aquilegia | Aquilegia spp. | Perennial | Late spring | Columbine; spurred flowers, hybridises freely |
| Amaranth | Amaranthus caudatus | Annual | Summer–autumn | Love-lies-bleeding; long crimson tassels |
Border and Bedding Staples
Aster
Asters flower when almost everything else has finished, which makes them one of the most valuable late-season nectar sources before winter. Most North American species were reclassified out of Aster into Symphyotrichum and related genera in the 1990s, so nursery labels and older books often disagree — the plants are the same. They divide easily and benefit from being split every few years.
Allium
Ornamental onions, grown for perfectly spherical heads made of dozens of small star-shaped flowers. The foliage yellows and dies as the flowers open, so alliums are best planted behind something that hides their feet. Seedheads hold their shape for months and are worth leaving standing into winter.
Alstroemeria
The Peruvian lily, and one of the best cut flowers there is — two to three weeks in a vase is normal. Pull the stems from the base rather than cutting them; that stimulates more growth from the tuberous roots. The streaked and speckled markings on the inner petals act as nectar guides.
Antirrhinum
The snapdragon, named for the hinged flower that opens like a mouth when squeezed at the sides. That hinge is a pollination mechanism: the flower is heavy enough that only a bumblebee can force it open, which excludes lighter insects that would take nectar without transferring pollen. The dried seed capsules look startlingly like small skulls.
Astilbe
Feathery plumes in white, pink and red above finely divided foliage. Astilbe is unforgiving about one thing: it must have consistently moist soil. In dry ground the leaf edges scorch brown within days and the plant sulks for the rest of the season. Give it shade and damp and it is otherwise trouble-free.
Angelonia
Summer snapdragon, though it is not closely related to the true snapdragon. It flowers continuously through the hottest part of summer without deadheading, which is unusual, and it tolerates humidity that makes many bedding plants collapse.
Ageratum
Floss flower, producing dense clusters of fluffy blue-mauve blooms with no visible petals — the effect comes entirely from projecting stamens. It is one of relatively few genuinely blue annuals for edging.
Alyssum
Lobularia maritima forms low carpets of tiny honey-scented flowers from spring until frost. The scent is strongest in warm sun. Shearing it back by a third when it tires in midsummer brings a full second flush.
Amaranth
Love-lies-bleeding, Amaranthus caudatus, hangs long crimson tassels that can reach half a metre. It is the ornamental relative of the grain amaranth eaten across Central America and South Asia, and the seed of this species is edible too.
Bulbs, Tubers and Rhizomes
Amaryllis
The bulbs sold as amaryllis for winter forcing are really Hippeastrum; true Amaryllis is the South African belladonna lily. They produce enormous trumpets on hollow stems, often before any leaves appear. Do not discard after flowering — feed the foliage through summer and give a dry rest in autumn, and the bulb reflowers for years. The bulbs contain lycorine and are toxic to people and pets.
Anemone
Windflower, and effectively two different garden plants under one name. Spring anemones grow from small tubers, are low and woodland-suited, and vanish by summer. Autumn-flowering Japanese anemones are tall fibrous-rooted perennials that spread steadily and flower from late summer into October. Buying one expecting the other is a common disappointment.
African Lily
Agapanthus carries rounded heads of blue or white trumpets on tall bare stems. It flowers far better when the roots are crowded, so it is one of the few plants that genuinely performs best left in a tight pot for years. Deciduous types are considerably hardier than evergreen ones.
Arum Lily
The calla lily, Zantedeschia aethiopica. What looks like a single white petal is a spathe, a modified leaf wrapped around the yellow spadix that carries the true flowers. It grows in boggy ground and even in shallow water. All parts contain calcium oxalate crystals, which cause burning and swelling in the mouth if chewed and irritate skin on contact with the sap.
Anthericum
St Bernard’s lily, a modest alpine perennial with airy spikes of small white star-shaped flowers in late spring. It is undemanding in well-drained soil and slowly forms clumps.
Shrubs, Climbers and Foliage
Azalea
Azaleas are rhododendrons — the distinction is horticultural, not botanical, with azaleas generally smaller-leaved and often deciduous. They demand acid soil; in alkaline ground the leaves yellow between the veins as iron becomes unavailable, and no amount of feeding fixes it permanently. Grow them in ericaceous compost in pots if your soil is limy.
Warning: all parts of azaleas and rhododendrons contain grayanotoxins, which disrupt sodium channels and cause vomiting, low blood pressure and heart rhythm disturbance if eaten. Honey made predominantly from these flowers — historically called “mad honey” — can carry enough toxin to affect people.
Abelia
A reliable shrub flowering from midsummer until autumn, with small scented tubular blooms. The persistent pink-bronze sepals stay on after the petals drop and keep the plant looking coloured for weeks longer than it is actually in flower.
Acanthus
Bear’s breeches, grown as much for the huge architectural leaves as for the tall hooded flower spikes. That leaf is the model for the ornamentation on Corinthian columns and has been a decorative motif for well over two thousand years. Be certain before planting: the deep brittle roots regenerate from fragments, making it very hard to remove.
Aloe
Succulents from Africa and Arabia with tubular red, orange or yellow flowers on tall spikes, typically in winter — and bird-pollinated in habitat, which is why the flowers are held clear of the spiny rosette. Aloe vera is the familiar species, though most aloes are grown as ornamentals rather than for gel.
Anthurium
Like the arum lily, the glossy red or pink “flower” is a spathe surrounding the true flowers on the central spadix. That structure is why anthuriums look permanently in bloom — the spathe persists for weeks. They want warmth, humidity and bright indirect light, and they also contain calcium oxalate.
Ground Cover and Rockery Plants
Alchemilla
Lady’s mantle, grown for pleated leaves that hold rainwater in perfect silver beads — a water-repellent leaf surface, and the reason alchemists thought the collected droplets were purer than ordinary water, which gave the plant its name. Sprays of tiny lime-green flowers froth over paths in early summer. It self-seeds enthusiastically.
Aubrieta
Cascades of purple, mauve or pink over walls and rockeries in spring, forming sheets of colour. Cut it back hard immediately after flowering; left alone it becomes woody and bare in the middle within a couple of seasons.
Armeria
Sea thrift, a neat cushion of grassy foliage with round pink flower heads on wiry stems. It grows naturally on coastal cliffs and salt marsh, so it tolerates salt spray, wind and thin poor soil better than almost any other small perennial.
Arabis
Rock cress, forming spreading mats topped with white or pink cross-shaped flowers in spring. Like aubrieta it belongs in walls, gravel and rockeries, and like aubrieta it needs cutting back after flowering to stay compact.
Achillea
Yarrow, with flat plates of tiny flowers held above finely dissected ferny foliage. The flat heads are ideal landing platforms for hoverflies and small beneficial insects. It thrives on poor dry soil and flops badly on rich ground — one of the few plants actively harmed by good conditions.
African Daisy
Osteospermum closes its flowers at night and on overcast days, reopening in sun. That habit is worth knowing before planting it somewhere shaded, where it may barely open at all. It flowers over a very long season in full sun.
Aquilegia
Columbine, with nodding spurred flowers where the backward-pointing spurs hold nectar reachable only by long-tongued bees and hummingbirds. Aquilegias hybridise so freely that seedlings almost never resemble the parent — charming if you want variety, frustrating if you wanted a specific colour.
The Most Dangerous Flower on This List
Aconite
Aconitum, known as monkshood or wolfsbane, produces tall spires of deep blue hooded flowers in late summer and autumn, when little else of that colour is in bloom. It is a genuinely beautiful border plant — and the most dangerous entry in this guide.
Warning: aconite is among the most poisonous plants grown in gardens. All parts contain aconitine and related alkaloids, with the roots most concentrated. Aconitine acts on sodium channels in nerve and heart tissue, causing tingling and numbness, vomiting, and cardiac arrhythmia that can be fatal; there is no specific antidote and treatment is supportive. Poisonings have occurred when the root was mistaken for horseradish. The toxins can also be absorbed through broken skin, so wear gloves when dividing or handling it, wash afterwards, and do not grow it where children or pets forage. If you are unwilling to manage that, choose delphinium or a tall campanula for the same colour and height instead.
Angel’s Trumpet
Brugmansia hangs enormous pendant trumpets, often 30 cm long, which release a powerful scent after dark to attract night-flying moths. It is a striking container shrub in warm climates. It is also closely related to datura and shares its chemistry.
Warning: all parts of Brugmansia are severely toxic, containing tropane alkaloids including scopolamine and atropine. Ingestion causes delirium, hallucinations, rapid heartbeat and can be fatal, and alkaloid concentration varies so widely between plants and seasons that no quantity is predictable. Brugmansia is extinct in the wild and survives only in cultivation. Handle with gloves and keep it away from children.
Growing Notes
For dry, poor soil: achillea, armeria, aubrieta, arabis, allium and aloe all prefer thin ground and suffer in rich, damp conditions. For moist shade: astilbe, alchemilla, anemone and arum lily. Longest flowering: alyssum, angelonia, ageratum and abelia run from early summer to frost. Best cut flowers: alstroemeria for vase life, allium for seedheads, antirrhinum for height.
For late-season colour when most borders are finishing, asters, Japanese anemones and aconite all peak from late summer into autumn — though only two of those three are safe around children.
Frequently Asked Questions
What flowers start with the letter A?
Twenty-eight are covered here, including aster, azalea, allium, alstroemeria, amaryllis, anemone, antirrhinum (snapdragon), aquilegia, astilbe, alyssum, achillea, acanthus, armeria, aubrieta, alchemilla, anthurium, arum lily, African lily (agapanthus), African daisy, angelonia, ageratum, abelia, aloe, arabis, amaranth, anthericum, aconite and angel’s trumpet.
Which flower starting with A is most poisonous?
Aconite (monkshood), without question. All parts contain aconitine, the roots most of all, and it can disturb heart rhythm fatally. Angel’s trumpet is also severely toxic, and azalea, amaryllis bulbs and arum lily are all poisonous to a lesser degree.
What is the easiest A flower to grow?
Alyssum from seed, or aubrieta and armeria if you want something permanent. All three tolerate poor soil, need no feeding and flower reliably. Alstroemeria is the easiest for cutting, and asters are the easiest for late-season colour.
Why won’t my agapanthus flower?
Usually too much room or too much nitrogen. Agapanthus flowers best when the roots are congested, so leave it pot-bound and feed with a high-potash rather than high-nitrogen feed. Deciduous varieties are also hardier than evergreen ones, which may be shy after a cold winter.
Is an azalea the same as a rhododendron?
Botanically yes — azaleas sit within the genus Rhododendron. The distinction is horticultural: azaleas are generally smaller-leaved, often deciduous, and carry fewer stamens. Both need acid soil and both are toxic.
Which A flowers are best for pollinators?
Achillea and allium for hoverflies and bees, aster for late-season nectar when little else remains, alyssum for small beneficial insects, and aquilegia for long-tongued bumblebees that can reach into the spurs.
Sources
Aconitine toxicology and clinical presentation: standard clinical toxicology references and national poisons information services. Grayanotoxin content of Rhododendron and mad honey poisoning: peer-reviewed toxicology literature. Tropane alkaloids in Brugmansia: clinical toxicology literature. Aster reclassification to Symphyotrichum: current botanical nomenclature.
This article is for general information. Never eat any flower, bulb or root unless you are certain of its identification — several plants listed here are toxic and one is potentially fatal.
