Euphorbia albomarginata

Torr. & A.Gray (1857)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-Rosids Order: Malpighiales Family: Euphorbiaceae Genus: Euphorbia

rattlesnake weed

Description

Key Characters:

Growth Form: Glabrous, low perennial herbs from a woody taproot.

Stems: Stems several to numerous, prostrate and often rooting at the nodes, 0.1–0.35 m long, many branched.

Roots:

Leaves: Leaves simple. Opposite. Blades orbicular to oblong, 3–8 mm long, 2–7 mm wide. Apex rounded, occasionally emarginate or apiculate. Surfaces glabrous. Margins entire. Petioles 0.5–1.2 mm long. Stipules on both sides of the stem connate into a white, membranous, deltate to lanceolate scale 1–2 mm long, margins entire to lacerate.

Flowers: Flowers in cyathia solitary at the nodes and in the forks; staminate flowers 15–30 per cyathium. involucre turbinate, ca. 1 mm high, glands 4, shallowly cupped, oblong, 0.5–1 mm long, appendages of the glands usually conspicuous, white, 1–3 times as long as the gland is wide. Flowers unisexual and highly reduced. Pistillate flowers solitary, on a gynophore; staminate flowers in 5 groups or cymules, each with 1 to several flowers. Calyx (sepals) absent. Corolla (petals) absent. Male flower reduced to a single stamen, with an articulation at junction of pedicel and filament, subtended by slender bracteoles. Ovary superior, 3-carpellate; ovules 1 per cell, anatropous.

Fruit: Capsules ovoid; 3–angled; 1.3–2 mm long. Seeds pale brown with a white coat; 4–angled; 1.2–1.7 mm long; the faces smooth or minutely puncticulate in transverse lines.

Ploidy: 2n = 36; 48

Habitat: Coastal areas.

Elevation Range:

Historical Distribution

Uses and Culture

USES

Natural History

Statewide Status

Potentially Naturalizing

Island Status

O'ahu Potentially Naturalizing

Dispersal Agents


Pollinators

Bibliography

Name Published In: Pacif. Railr. Rep. Pope, Bot. 2(4): 174 (1857)

Other References

Wagner et al. 1990:604 (K, O [as Chamaesyce albomarginata, 2 colls. on O‘ahu, Hālawa Park, 1947 & 1950]); Wagner et al. 1997:56 (remove K [spms. reidentified as C. serpens], KEY); Govaerts et al. 2000:667 (NOM:Syn. C. albomarginata = Euphorbia albomarginata); Steinmann & Porter 2002/Yang & Berry 2011 (molecular support for nesting of Chamaesyce within Euphorbia)

Occurrences

SNo. Scientific Name Scientific Name Authorship Locality Habitat Basis of Record Recorded By Record Number Island Source Date
1 Euphorbia albomarginata Torr. & A.Gray near halawa park, pearl harbor In high pool on tuff bench at north side of entrance to bay. PRESERVED_SPECIMEN degener, o. collector number: 25000 Oahu BISH 12/10/1950
2 Euphorbia albomarginata Torr. & A.Gray Mahaulepu, Kipu side, before barbwire fence running to edge of seacliff. PRESERVED_SPECIMEN Natalia Tangalin 92 Kauai PTBG 6/15/2004
3 Euphorbia albomarginata Torr. & A.Gray Maha'ulepu. Littoral vegetation in sand pickets over lithified dunes. PRESERVED_SPECIMEN Tim Flynn 4253 Kauai PTBG 9/28/1990
4 Euphorbia albomarginata Torr. & A.Gray Ahukini Recreational Pier State Park on southeastern corner of Hanamaulu Bay. PRESERVED_SPECIMEN Tim Flynn 1069 Kauai PTBG 4/11/1985
5 Euphorbia albomarginata Torr. & A.Gray Housing area between Honolulu and Pearl Harbor PRESERVED_SPECIMEN Kerr, M. 21.702 Oahu BISH 5/3/1947
6 Euphorbia albomarginata Torr. & A.Gray Poipu. Sheraton Poipu, in and around parking lot, west of makai wing. PRESERVED_SPECIMEN Tim Flynn 4258 Kauai PTBG 10/2/1990
7 Euphorbia albomarginata Torr. & A.Gray Common near lighthouse, Ninini Point, Lihu'e. PRESERVED_SPECIMEN Lynwood Hume 308 Kauai PTBG 3/28/1988
8 Euphorbia albomarginata Torr. & A.Gray Near Halawa Yack, Pearl Harbor PRESERVED_SPECIMEN Degener, O.; Degener, I. 25000 Oahu US 12/10/1958
9 Euphorbia albomarginata Torr. & A.Gray near halawa yack, pearl harbor PRESERVED_SPECIMEN o. degener & i. degener 25000 Maui US 12/10/1958
10 Euphorbia albomarginata Torr. & A.Gray housing area between honolulu and pearl harbor PRESERVED_SPECIMEN kerr, m. collector number: 21.702 Oahu BISH 5/3/1947
11 Euphorbia albomarginata Torr. & A.Gray Near Halawa Park, Pearl Harbor PRESERVED_SPECIMEN Degener, O. 25000 Oahu BISH 12/10/1950