Succulent identification: how to identify succulents by shape, leaf and sap

Rosettes: Echeveria vs Sempervivum vs Graptopetalum

All three are in the stonecrop family (Crassulaceae) and all three form rosettes, so the label "hens and chicks" lands on each of them. The UF/IFAS Extension succulents page points out that the name is used for Sempervivum, Echeveria, Sedum and others, and that the Latin name is the only clear one.

Sempervivum (houseleek). Native to Europe and described by UF/IFAS as exceptionally cold hardy, so a rosette that has lived outdoors through hard frosts points toward Sempervivum; in England and Wales houseleeks were traditionally grown on roofs. Look for the "chicks": small rosettes packed around the parent. A cobweb of fine white hairs across the center is the signature of Sempervivum arachnoideum, the cobweb houseleek.

Echeveria. A large group of mostly small rosettes, often only a couple of inches across, sold in pots in every color from blue-green to near black ('Black Prince'). UF/IFAS gives the blue rose echeveria (Echeveria imbricata), a native of Mexico, as the classic look: blue-green leaves with hints of pink, shaped like an open rose. With so many hybrids in the trade, a genus name is often the honest answer.

Graptopetalum (ghost plant). The NC State Extension Plant Toolbox describes Graptopetalum paraguayense as rosettes 3 to 6 inches across held at the tips of stems that keep growing and eventually hang over the pot edge. The leaves are whitish green, turning pink-tinged in hot, dry weather and bluish in partial shade. In spring it bears small star-shaped white flowers with small red dots. Rosettes on the end of long, sprawling stems plus a whitish pastel color point to ghost plant rather than an echeveria.

Aloe family: Aloe vs Haworthia vs Gasteria

These three belong to the aloe family (Asphodelaceae), and Wisconsin Extension notes that haworthias were once classed in the genus Aloe. They have firmer, pointed leaves than the stonecrop rosettes above.

• Aloe. NC State's aloe page gives the quick ID: a rosette of fleshy, lance-shaped leaves, often with white dots, serrate (toothed) margins, and soft leaves that break easily to show a gel-like sap. Tubular flowers cluster densely along leafless stalks. The genus has more than 500 species, from small rosettes to tree forms.
• Haworthia. Small: Wisconsin Extension's haworthia article puts single plants at 1 to 3 inches across. The leaves may be thin and bristly or thick and fat, plain or marked with lines, bumps, stripes or dots, and many plants produce offsets. The flowers are small and whitish.
• Gasteria. A smaller related genus of about 15 species, with red to orange flowers (Wisconsin Extension).

Field test: a large rosette with toothed edges and gel inside is an aloe. A rosette that fits in the palm, with bumps or stripes and small whitish flowers, is a haworthia. If a plant of this family flowers red or orange, look at Gasteria.

Jade plant vs elephant bush

The pair people confuse most. The NC State jade plant page describes Crassula ovata as a South African succulent shrub that takes the form of a miniature tree, with oval, egg-shaped, smooth-edged leaves and thick branched stems that carry prominent scars. It seldom flowers in homes; outdoors it bears tiny pink flowers in spring. Some cultivars change the leaf completely: 'Gollum' has tubular leaves with a suction-cup tip.

Elephant bush (Portulacaria afra) is sold as dwarf jade or miniature jade, but Wisconsin Extension's elephant bush article stresses that it is not related to jade plant. Its glossy, emerald-green leaves are only ½ to ¾ inch long, round to oval, almost stalkless and set in opposite pairs on brittle, reddish-brown stems that turn grayish with age. The test: jade has larger leaves on thick trunks; elephant bush has much smaller leaves closer together on thinner, reddish stems. The jade plant profile has the full ID card.

Sedums and the trailing succulents

Sedum (stonecrop). UF/IFAS describes sedums as ranging from a few inches to 3 feet tall, some trailing over container edges. In practice they fall into two groups you can see at a glance: low, creeping mats and ground covers (Sedum spurium cultivars such as 'Dragon's Blood', the chartreuse 'Angelina') and taller, upright plants up to about 3 feet. With so many species and cultivars, a genus name is the realistic target.

Burro's tail or donkey tail (Sedum morganianum). UF/IFAS describes trailing stems surrounded by smooth, lance-shaped, overlapping leaves that together look like an animal's tail. It is a sedum, so it belongs with the stonecrops above, not with the bead-leaved plant below.

String of pearls (Curio rowleyanus, formerly Senecio rowleyanus). The NC State string of pearls page describes tiny, pea-shaped leaves on trailing stems that spill over a pot like a string of beads; it is native to dry areas of South Africa and was moved from Senecio to Curio. The test against burro's tail: separate round beads on a thin stem, not overlapping lance-shaped leaves hiding the stem. NC State lists string of pearls as toxic to both people and pets, so hang it out of reach and check the plants toxic to cats guide if you share your home with one.

Cactus vs euphorbia: spines, thorns and milky sap

Many succulent euphorbias look exactly like cacti: thick, fleshy, angled stems with spines. Three checks tell them apart, and the third matters for your skin. Once you know it is a true cactus, the cactus identification guide takes it to a genus.

1. Where the spines start. On a cactus, spines grow from areoles. NC State's Euphorbia page notes that cactus-like euphorbias have symmetrical pairs of spines arising from a shield or from old flower stalks, and not from areoles. Some euphorbias carry thorns on leafy, woody stems instead.
2. Flowers. Euphorbia flowers are tiny and nondescript, often surrounded by showy bracts (the poinsettia is a euphorbia).
3. Sap. NC State states that every euphorbia releases a toxic milky latex when cut. The sap can irritate skin or open wounds and cause nausea or vomiting if swallowed. Don't cut a plant to test it: if a broken stem already shows white sap, treat it as a euphorbia, wear gloves and wash off any sap that reaches your skin.

When a photo helps

A succulent is easy to photograph and hard to name, because so many are hybrids. Take one sharp photo of the whole plant from slightly above, with a leaf edge and any flower in view. Plant Identifier gives a common and scientific name from that one photo; it shows no confidence score and no list of alternative species, so confirm the answer with the field tests above. The app's Collection catalog has a succulent group of 20 entries that fills in as you identify plants, and the Toxicology tool in Plant Identifier gives AI-written notes on cats and dogs that you should check with your vet. For a houseplant that isn't a succulent, the houseplant identification key works through leaf shape and growth habit one question at a time.