Euphorbia hyssopifolia L., Euphorbiaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Chamaesyce hyssopifolia (L.) Small; Euphorbia brasiliensis Lam.

Common name(s): [more details]

English: hyssop-leaf sandmat

Habit:  herb

Description:  "Erect to ascending annual herb up to 60 cm or more in height with red or green, glabrous stems and milky sap.  Leaves simple, opposite, blade oblong to linear-oblong, 0.8-3 cm long, round to obtuse at the tip, rounded to oblique at the base; surfaces glabrous or slightly pilose; margins serrate; petiole 1-2 mm long.  Inflorescence of leafy axillary cymes, ultimately in several cyathia with a tiny, glabrous, 4-lobed involucre bearing 5 glands and a pink or white appendage.  Corolla absent.  Female flower 1, consisting of 1 stamen.  Fruit a glabrous, 3-lobed, subglobose schizocarp 1.5-2 mm long, broadest below the middle, splitting into 3 one-seeded segments.  Distinguishable by its glabrous herbaceous stems, milky sap, opposite leaves, short leafy cymes, tiny white-flowered cyathia (a kind of inflorescence), and tiny 3-lobed splitting fruit.  Easy confused with Euphorbia hypericifolia."  (Whistler & Steele, 1999; p. 48).

Habitat/ecology:  In Hawai‘i, "sparingly naturalized in low elevation, dry, disturbed sites" (Wagner et al., 1999; pp. 610, 1874).  On Kwajalein, Marshalll Islands, "uncommon as a weed of disturbed places" (Whistler & Steele, 1999; p. 48).

Propagation:  Seed

Native range:  "From southern United States to Argentina and the West Indies, naturalized in the Paleotropics" (Wagner et al., 1999; p. 610).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
American Samoa Tutuila Islands	Tutuila Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1991) (voucher ID: PTBG 37015) Taxon name on voucher: Chamaesyce hyssopifolia (L.) Small
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 610) Voucher cited: Stone 3014 (BISH)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 610)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Herbarium Pacificum Staff (1999) (p. 3) Voucher cited: C. Imada 98-2 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 610)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Oppenheimer, Hank L. (2003) (p. 11) Voucher cited: Oppenheimer H70115 (BISH, PTBG)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 610)
Japan (offshore islands) Bonin (Ogasawara) Islands	Bonin (Ogasawara) Islands	introduced	Kato, Hidetoshi (2007)
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	introduced invasive	Whistler, W. A./Steele, O. (1999) (p. 48) Vouchers cited: Herbst 8949, Whistler 11189
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1998) (voucher ID: PTBG 43963) Taxon name on voucher: Euphorbia hyssopifolia
United States (other Pacific offshore islands) Midway Atoll	Midway Atoll	introduced invasive	Bruegmann, Marie M. (1999) (p. 2) Voucher cited: Bruegmann 2029 (BISH) Uncommon

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
China China	China (People's Republic of)	introduced invasive	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011) Disturbed areas along railways and roads. Hainan.
Japan Japan	Japan (country)	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 186)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011) Also Central and South America
Taiwan Taiwan	Taiwan Island	introduced invasive	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011) Disturbed areas along railways and roads.

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	United States (other states)	native	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2011)

Additional information:
Additional online information about Euphorbia hyssopifolia is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Euphorbia hyssopifolia as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Euphorbia hyssopifolia may be available from the Germplasm Resources Information Network (GRIN).

References:

Bruegmann, Marie M. 1999. New records of flowering plants on Midway Atoll. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 1998. Part 2: Notes. Bishop Museum Occasional Papers. 59:1-2.

Herbarium Pacificum Staff. 1999. New Hawaiian plant records for 1998. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 1998. Part 1: Articles. Bishop Museum Occasional Papers. 58:3-11.

Kato, Hidetoshi. 2007. Herbarium records of Makino Herbarium, Tokyo Metropolitan University. Personal communication.

Mito, Toshikazu/Uesugi, Tetsuro. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2)/2004: 171-191.

National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.). 1991. Voucher specimen #PTBG37015(Art Whistler 8045).

National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.). 1998. Voucher specimen #PTBG43963 (Art Whistler 11189).

Oppenheimer, Hank L. 2003. New plant records from Maui and Hawai‘i Counties. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2001-2002. Part 1: Articles. Bishop Museum Occasional Papers. 73:3-30.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

U.S. Dept. Agr., Nat. Res. Cons. Serv. 2011. The PLANTS Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).

Whistler, W. A./Steele, O. 1999. Botanical survey of the United States of America Kwajalein Atoll (USAKA) Islands. Prepared for Oak Ridge Institute for Science and Education and the U. S. Army Environmental Center. 111 pp.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).