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Trianthema portulacastrum

L. (1753)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-CoreEudicot Order: Caryophyllales Family: Aizoaceae Genus: Trianthema

horse purslane, trianthema

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Description

Key Characters:

Growth Form: Perennial herbs.

Stems: Prostrate or ascending, somewhat succulent, up to 5 dm long, sometimes more, glabrous or sparsely pubescent.

Roots:

Leaves: Leaves simple. Opposite. Blades flat, elliptic to obovate or spatulate, 1–2(–4) cm long, 0.4–2(–3) cm wide. Apex obtuse or retuse. Base rounded to cuneate. Surfaces glabrous. Margins entire to undulate. Petioles 0.5–2.5 cm long, expanded into a sheath connate with opposing leaf base to form a cup. Stipules absent.

Flowers: Flowers solitary, sessile, largely hidden in leaf axils. Flowers bisexual (perfect). Calyx of 5 sepals, sepals adnate to leaf base, the lobes linear to narrowly deltate, 4–5 mm long, inner surface pink or white, sparsely pubescent externally. Corolla (petals) absent. Stamens 6 to numerous, adnate to upper edge of floral tube. Ovary superior, cylindrical; style ca. 2 mm long. Operculum truncate, 2–3 mm long, with a prominent raised, denticulate rim along outer side.

Fruit: Capsules with circumscissile dehiscience; with a persistent perianth; the operculum flat; ovoid or subglobose. Seeds dull black; reniform; 1.5–2 mm wide; weakly ridged.

Ploidy: 2n = 26; 28

Habitat:

Elevation Range:

Historical Distribution

Uses and Culture

USES

Natural History

Statewide Status

Naturalized

Island Status

Kaua'i Naturalized
O'ahu Naturalized
Kaho'olawe Naturalized
Maui Naturalized

Dispersal Agents


Pollinators

Notes

  • Description digitized by Pumehana Imada

Bibliography

Name Published In: Sp. Pl.: 223 (1753)

Other References

Wagner et al. 1990:179 (O); Herbst & Wagner 1996:9 (WM); Lorence & Flynn 2006:2 (K); Starr & Starr 2018:3 (Ka)

Wagner, W. L., Herbst, D. R., & Sohmer, S. H. (1999). Manual of the Flowering Plants of Hawai'i, Vols. 1 and 2 (No. Edn 2). University of Hawai'i and Bishop Museum Press.

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Description Recorded By Record Number Island Source Date
1 Trianthema portulacastrum Mokulua South, Oahu. On S side near coast near coast Preserved_Specimen Rare. A couple mature plants and a bunch of seedlings on south side near coast. Starr, F. 5022328 Oahu BISH 2005-02-23
2 Trianthema portulacastrum Ka‘ena Point Keawaula Section. At trail head just east of signage. Ocean side of trail. Leucaena leucocephala overstory. Weedy vegetation common along the entire trail until the enclosure fence including Chloris barbata, Sida ciliaris, Eleusine indica, Dictyloctenium aegyptium, Verbesina encelioides, Malvastrum americanum, Commelina benghalensis, Trianthema portulacastrum, Asystasia gangetica, Preserved_Specimen Kennedy, B. 127 Oahu BISH 2021-01-24
3 Trianthema portulacastrum Honokanaia, on ridge just past the bay on side of K1. Dry coastal scrub with Prosopis pallida, Cenchrus ciliaris. In gravelly/rocky edge. Preserved_Specimen Widely scattered here and elsewhere. Naturalized. Starr, F. 17121401 Kahoolawe BISH 2017-12-14
4 Trianthema portulacastrum W Maui, Launiuopoko Beach Park Associated vegetation: Portulaca oleracea, Boerhavia coccinea. Preserved_Specimen Prostrate herb <1m ht; flowers pink to purple, open during overcast day, hidden in axils; lvs opposite, green w. red margins, flat somewhat succulent; fruit circumscissile capsule. Starr, F. 107012 Maui BISH 2001-07-01
5 Trianthema portulacastrum Ewa Dist.; near Koa Ridge, N of Kipapa Gulch E of H2 Hwy In ruderal vegetation abutting a pineapple field. Assoc. w/Sida ciliaris, Panicum maximum & other grasses. Preserved_Specimen Prostrate herb. Funk, E.J. Oahu BISH 1996-02-02
6 Trianthema portulacastrum Honouliuli, West Loch Along the old railroad right of way at the mouth of the stream. Preserved_Specimen Woodside, D. Oahu BISH 1990-06-16
7 Trianthema portulacastrum Waipio Peninsula; Waipio, Pouhala Marsh between Kapakahi & Waikele Streams Occasional on dredged ruderal land adjacent to the marsh. Preserved_Specimen Prostrate herb. Imada, C. 9619 Oahu BISH 1996-12-18
8 Trianthema portulacastrum Kaneohe; Kaneohe Community Garden Preserved_Specimen Sprawling herb; perianth pink; frt bright red to dark red, indurate. Nagata, K.M. 4275 Oahu BISH 1993-12-01
9 Trianthema portulacastrum Koloa, coffee field S of Niho Road, lower Kalaheo Preserved_Specimen herb; prostrate decumbent stems to 50-60 cm long; leaves and stems succulent; flower tiny, pink; fruit purple, seeds black Lorence, D.H. 9168 Kauai BISH 2003-09-22
10 Trianthema portulacastrum Southeast Oahu, on proposed park site near the turn in Kalanianaole Hwy that leads to Makapuu Overlook. Plant common in disturbed areas. Preserved_Specimen Funk, E.J. Oahu BISH 1991-10-20
11 Trianthema portulacastrum Kailua, Enchanted Lake HUMAN_OBSERVATION Imada, C. Oahu 11/3/2005
12 Trianthema portulacastrum Niu Valley. Wastland area (former pastureland). Preserved_Specimen Kumashiro, B. Oahu BISH 1991-03-15
13 Trianthema portulacastrum Makapuu, on mauka side of entrance to Sea Life Park Weed in graded area, growing along with other weeds: Cynodon dactylon, Verbesina, Amaranthus spinosus, Chloris, Setaria, Merremia. Preserved_Specimen Flat, spreading herb. Imada, C. 200015 Oahu BISH 2000-05-21
14 Trianthema portulacastrum Pearl Harbor National Wildlife Refuge HUMAN_OBSERVATION Imada, C. Oahu 2/23/2005
15 Trianthema portulacastrum Salt Lake area, behind Gumnasium of Saltlake Elementary School Preserved_Specimen Herbst, D.R. Oahu BISH 1976-01-20
16 Trianthema portulacastrum Pearl Harbor; Pearl City Peninsula, near Surtass Bldg Preserved_Specimen Funk, E.J. Oahu BISH 1991-08-13
17 Trianthema portulacastrum W Maui, Lahaina District, Lahaina Town Sprawling in roadside waste area. Preserved_Specimen Flowers pink. Oppenheimer, H.L. 90001 Maui BISH 2000-09-25
18 Trianthema portulacastrum Koloa, S of Niho Road, lower Kalaheo coffee field Preserved_Specimen herb; prostrate, decumbent stems to 50-60 cm long; leaves and stems succulent; flower tiny, pink; fruit purple, seed black Lorence, D.H. 9168 Kauai BISH 2003-09-22
19 Trianthema portulacastrum W Maui, Launiupoko, Kapuali Along cane field road. Preserved_Specimen Low spreading herbs, c..3m tall 3X.9m wide. Flowers solitary in axils,5-6petals, pink, entire 2-3mmX2mm, anthers 12-18, fruit blunt, tippped w/dried remains of unbranched style, imbedded in axil. Hobdy, R.W. 3543 Maui BISH 1993-03-05
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