PlantNET Home DONATE TODAY | PlantNET Home | Search NSW Flora | Contact Us  
Plant Name Search
Index Search
Spatial Search
Identification Keys
Telopea Journal
Other Data Sources

Genus Euphorbia Family Euphorbiaceae

Synonyms: Chamaesyce APNI*
Monadenium APNI*
Synadenium APNI*
Pedilanthus APNI*
Poinsettia APNI*

Description: Herbs or shrubs, sometimes succulent, latex whitish; mostly monoecious.

Leaves alternate, opposite or whorled; stipules present or absent.

Inflorescence unit a cyathium; cyathia solitary or borne in terminal or axillary cymes or clusters or pseudoaxillary cymes. Cyathia are flower-heads resembling single flowers, each cyathium with a solitary terminal female flower surrounded by 4 or 5 male cymes (male flowers in cymes of 1–several flowers), all enclosed by a cup-shaped involucre with lobes or teeth alternating with 1–5 glands, the latter sometimes bordered by petaloid appendages; male cymes 1–10-flowered. Male flowers each with 1 stamen, perianth usually absent. Female flower consisting of a stalked (pedicellate) 3-locular ovary, styles 3, free or basally fused, mostly bifid; perianth 3–6 scale-like sepals or absent.

Capsule exserted beyond involucre, separating into three 2-valved segments; seeds with or without caruncle.

Distribution and occurrence: World: >1500 species, chiefly subtropical & warm-temp. regions. Australia: c. 81 species (at least 26 species naturalized), all States.

Euphorbia sens. lat. includes a wide diversity of vegetative forms from smally leafy annuals and prostrate herbs to shrubs and cactus-like trees. One group of morphologically similar plants is the formerly recognised Chamaesyce species that are usually distinguished by having prostrate stems, opposite leaves (with an asymmetric base), obvious stipules and seeds without a caruncle. This group is included in Euphorbia section Anisophyllum, following D.A. Halford & W.K. Harris, A taxonomic revision of Euphorbia section Anisophyllum Roeper (Euphorbiaceae) in Australia, Austrobaileya 8(4): 441-600 (2012), which provides a comprehensive account and key to species in the section.

Text by adapted from T.A. James & G.J. Harden, Fl. NSW Vol. 1 (1990); updated March 2017, PGK
Taxon concept: Australian Plant Census (accessed March 2017)

Taxa not yet included in identification key
Euphorbia ferdinandi,    Euphorbia inappendiculata,    Euphorbia multifaria,    Euphorbia oblongata,    Euphorbia ophthalmica,    Euphorbia papillata,    Euphorbia papillifolia,    Euphorbia porcata,    Euphorbia serpens,    Euphorbia thelephora,    Euphorbia verrucitesta

 Key to the species 
1Stems erect; leaves usually alternate on lower stems, subopposite or opposite above; stipules minute or absent2
Stems prostrate, decumbent or ascending; leaves opposite; stipules present, interpetiolar (includes species formerly treated as Chamaesyce)18
2Shrubs or subshrubs, cyathia solitary (except in Euphorbia sarcostemmoides); native species3
Erect herbs; cyathia in compound inflorescences or solitary; naturalized weedy species
                       Back to 1
3Apparently leafless shrub, multistemmed; cyathia in compound cymesEuphorbia sarcostemmoides
Leafy shrubs or subshrubs, with a single main stem; cyathia solitary
                       Back to 2
4Leaves oblong-lanceolate to oblanceolate, ovate or oblong-spathulate; length:width ratio less than 6.5:15
Leaves linear to narrow-lanceolate, length:width ratio more than 7:1
                       Back to 3
5Capsules broader than long, more or less depressed-globose, c. 5 mm long, 6 mm diam.; seeds ovoid without a caruncle; leaves falling earlyEuphorbia stevenii
Capsule as long as or longer than broad, globose to triangular, 4–4.5 mm long, c. 4 mm diam.; seeds more or less oblong, carunculate; leaves more persistent
                       Back to 4
6Leaves with lamina to 25 mm long and 8 mm wide; seeds covered with pustules, caruncle crescent-shaped; an inland speciesEuphorbia parvicaruncula
Leaves with lamina to 50 mm long and 17 mm wide; seeds smooth to undulate; caruncle hat-shaped; a coastal species
                       Back to 5
Euphorbia tannensis
7Capsule oblong-ovoid, to 6 mm long, 4 mm diam.; seeds grey-brown, smooth to deeply wrinkled, caruncle hat-shaped, persistent, yellow-brownEuphorbia tannensis
Capsule more or less globose, c. 3 mm long, 3.5 mm diam.; seeds dark blue-green, deeply pitted-reticulate, caruncle small, crescent-shaped
                       Back to 4
Euphorbia planiticola
8Leaves mostly 40 mm or more long9
Leaves mostly less than 40 mm long
                       Back to 2
9Stem leaves sessile or shortly petiolate, margins entire or minutely toothed10
Stem leaves distinctly petiolate, margins entire to widely lobed or toothed
                       Back to 8
10Stem leaves entire, 60–160 mm long, 5–12 mm wide, opposite and decussateEuphorbia lathyris
Stem leaves finely toothed, particularly towards apex, 10–60 mm long, 8–25 mm wide, alternate, not decussate
                       Back to 9
11Stem leaves linear to oblong-elliptic, sessile; capsule c. 3.5 mm long, tuberculate; seeds smoothEuphorbia depauperata
Stem leaves obovate to spathulate, petiole c. 1 mm long; capsule c. 2 mm long, smooth; seeds reticulate-pitted
                       Back to 10
Euphorbia helioscopia
12Lamina entire to widely lobed, often reddish at base of upper leaves; glabrous to pubescentEuphorbia cyathophora
Lamina coarsely toothed, not reddish at base of upper leaves; pubescent
                       Back to 9
Euphorbia davidii
13Stem leaves sessile, variable, distinctly different in shape and/or colour from the leaves of the fertile branches14
Stem leaves petiolate (very shortly so in Euphorbia helioscopia), obovate to spathulate or ovate, not conspicuously different from leaves of fertile branches
                       Back to 8
14Stem leaves more than 10 mm wide; leaves of fertile branches with conspicuous white margins; capsule pubescentEuphorbia marginata
Stem leaves less than 10 mm wide; leaves of fertile branches without white margins; capsule glabrous
                       Back to 13
15Stem leaves more or less fleshy, crowded and imbricate; terminal cyathia solitaryEuphorbia paralias
Stem leaves not as above; terminal cyathia 2 or 3 (occasionally solitary in Euphorbia falcata)
                       Back to 14
16Glaucous annual; leaves of fertile branches broad-ovate, 1–10 mm wide, margins crenate; stem leaves oblong-cuneate to oblanceolate, 10–30 mm long, 2–5 mm wide, entireEuphorbia falcata
Green perennial; leaves of fertile branches ovate-triangular, 10–30 mm wide, margins finely toothed; stem leaves linear-lanceolate, 10–40 mm long, 2–8 mm wide, finely toothed
                       Back to 15
Euphorbia terracina
17Stems leaves with distinct petiole to 8 mm long; lamina obovate, mostly 10–15 mm long, margins entire; glands of involucre with horns at each endEuphorbia peplus
Stem leaves shortly petiolate, petiole c. 1 mm long; lamina obovate to spathulate, 10–40 mm long, margins toothed towards apex; glands of involucre entire
                       Back to 13
Euphorbia helioscopia
18Leaves 2–15 mm long; cyathia solitary in axils of leaves19
Leaves 10–40 mm long; cyathia in axillary or terminal cymes
                       Back to 1
19All or part of plant hairy; stems prostrate, often forming dense mats20
Plants glabrous; stems prostrate to ascending or rarely erect
                       Back to 18
20Entire plant covered with soft white hairs; native herb of inland plainsEuphorbia australis
Plants sparsely hairy, mainly on the stems and capsules; naturalized herbs of the coast and Western Slopes
                       Back to 19
21Stems with longitudinal bands of short white, often curled, hairs; capsule glabrous except for ciliate anglesEuphorbia prostrata
Stems with more or less scattered, longer, mostly spreading hairs; capsule sparsely hairy
                       Back to 20
Euphorbia maculata
22Annual 15–30 cm high with ascending to erect slender stems; leaves in more or less distant pairs along stems, leaves mostly 8–15 mm longEuphorbia wheeleri
Perennials with prostrate, ascending to almost erect or decumbent stems mostly to 20 cm long, often forming a woody rhizome; leaves more or less crowded along stems; leaves 2–10 mm long
                       Back to 19
23Leaves oblanceolate to oblong, margins often strongly recurved when dry; stipules mostly 1–1.5 mm long, more or less conspicuous, entire or divided, thread-likeEuphorbia inappendiculata var. queenslandica
Leaves ovate-oblong, margins not recurved when dry; stipules usually less than 1 mm long, inconspicuous, not thread-like (occasionally so in Euphorbia papillifolia var. polyandra)
                       Back to 22
24Appendages of glands conspicuous, crenate-sinuate; involucre c. 1.5 mm long; leaves glaucousEuphorbia papillifolia var. polyandra
Appendages of glands usually inconspicuous, mostly entire; involucre 0.5–0.7 mm long; leaves not glaucous
                       Back to 23
25Interpetiolar stipules triangular to broadly triangular, 0.2—1.1 mm long, entire or bipartite; capsule with a fringed receptacle appendage appressed to base (hypogynous disc laciniate or entire); seed faces more or less smoothEuphorbia dallachyana
Interpetiolar stipules subulate, 0.5–0.9 mm long, deeply bipartite; capsule without a fringed receptacle appendage (hypogynous disc entire); seed faces wrinkled
                       Back to 24
Euphorbia drummondii
26Plants persistently and densely hairy; cyathia in dense, stalked, head-like axillary cymesEuphorbia hirta
Plants glabrous or sparsely pubescent often glabrescent with age; cyathia not in dense heads
                       Back to 18
27Upper and lower leaves more or less consistent in size and shape; length:width ratio of leaves 2:1; lamina thick; prostrate plant forming mats on coastal sandsEuphorbia psammogeton
Upper leaves usually longer and narrower than lower leaves; length:width ratio of upper leaves more than 2:1; lamina thin; decumbent to ascending or semi-erect plants
                       Back to 26
28Hairs on stems scattered on all sides; length:width ratio of upper leaves 3:1 to 5:1; appendages of glands conspicuous, 1–2 mm wide, petaloid, whiteEuphorbia bifida
Hairs on stems usually confined to 1 or 2 sides; length:width ratio of upper leaves 3:1 or less; appendages of glands 0.5 mm wide, entire, white or pink
                       Back to 27
Euphorbia hyssopifolia

  Privacy | Copyright | Disclaimer | About PlantNET | Cite PlantNET