Euphorbia ingens E.Mey. ex Boiss., Euphorbiaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 7 (Go to the risk assessment)

Common name(s): [more details]

English: cactus euphorbia, cactus spurge, candelabra-tree, naboom

Habit:  tree

Description:  "Massive succulent tree to 4-12 (15) m high; trunk stout simple; bark rough fissured grey. Branches persistent from c. 3 m upwards, suberect, rebranching to form eventually a large broadly rounded crown; terminal branchlets fleshy, 4-angled, 6-12 cm wide, square in cross-section to distinctly but stoutly winged with wings to 3 cm wide, usually constricted at irregular intervals into oblong segments to 10-15 cm long or more; margins of the angles straight to sinuate bearing shallow tubercles 1-2 cm apart. Spine shields to 6 x 5 mm, very obtusely triangular, extending 5 mm above to include the flowering eye; spines stout, to c. 5 mm long; prickles flexible, triangular, 1.5 mm long, soon deciduous; spines and spine shields soon becoming corky, rusty-brown and disintegrating. Leaves to 8 x 2 cm and oblanceolate on seedlings and young growth, 3 x 3 mm and deltoid on older growth, and soon deciduous. Cymes crowded towards the apex of the branches, 1-3 at each flowering eye, 1-forked with stout peduncles to 8-20 mm long and cyme branches 5 mm long arranged vertically; bracts to 5 x 6 mm, rounded. Cyathia 5 x 10 mm, with broadly cup-shaped involucres; glands transversely elliptic, 2 x 4 mm, touching, golden-yellow; lobes transversely elliptic, 2.2 x 3 mm. Male flowers many: bracteoles spathulate, plumose; stamens c. 5.5 mm long. Female flower: perianth irregularly divided into 3 or more filiform lobes 2-4 mm long, sometimes with 1 or 2 teeth; styles 3 (rarely 2), 3-3.5 mm long, joined for 1.5 mm, apices thickened, rugulose, bifid. Capsule shortly exserted on a stout pedicel 5 mm long, (2)3-locular, subglobose, 7 x 10 mm, fleshy, green becoming red, hardening immediately before dehiscence to 6 x 9 mm, and very obtusely (2) 3-lobed. Seeds subglobose, slightly compressed laterally, to 4 x 3 mm, greyish-brown speckled with paler brown, smooth"  (Flora Zambesiaca online).

Habitat/ecology:  "Common from low to higher altitudes, usually solitary, in dry mopane and wooded grassland, often on rocky outcrops 10-1500 (1600) m"  (Flora Zambesiaca online). In Zimbabwe (native), "occurring in open woodland, often associated with rocky outcrops and termite mounds, up to 1670 m"  (Flora of Zimbabwe online).

Propagation:  Seed

Native range:  Botswana, Malawi, Mozambique, South Africa, Swaziland, Zimbabwe; also cultivated (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Cook Islands Southern Cook Islands	Ma‘uke Island	introduced cultivated	McCormack, Gerald (2013)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Lau, Alex/Frohlich, Danielle (2013) (pp. 6-7) Voucher cited: OED 2012030803 (BISH)
State of Hawaii Hawaiian Islands	O‘ahu Island		Bishop Museum (U.S.A. Hawaii. Honolulu.) (1997) (voucher ID: BISH 503015) Taxon name on voucher: Euphorbia ingens E. Mey. ex Boiss.

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Australia (continental)	introduced invasive	Randall, R. P. (2007) (p. 197)

Comments:  "Very similar to E. candelabrum Kotschy from east and northeast Africa, and may be conspecific (according to L.C. Leach). However, branches of the southern trees appear usually to be more distinctly and shortly segmented, the tubercle teeth along the angles are mostly further apart, and cymes are generally fewer at each flowering eye"  (Flora Zambesiaca online).

"As with many species of Euphorbia, the milky latex is poisonous and highly irritant to skin. When coming into contact with the eyes, it may cause temporary blindness"  (Flora of Zimbabwe online).

Control:  If you know of control methods for Euphorbia ingens, please let us know.