Glinus radiatus (Ruiz & Pav.) Rohrb.
Family: Molluginaceae
Spreading Sweetjuice
[Mollugo radiata Ruiz & Pav.]
Glinus radiatus image

Stems 0.8-5 dm. Leaves whorled; petiole 1-7 mm; blade obovate or elliptic to broadly spatulate, 5-25 × 2-17 mm, base cuneate, apex broadly rounded to acute. Flowers in clusters of 3-11; sepals lanceolate or oblong, 4.1-6.8 × 1.1-2.1 mm, stellate-pubescent abaxially, glabrous adaxially, apex long-acuminate to attenuate; stamens 3-5. Capsules ellipsoid, 3-3.5 mm. Seeds 10-25 per locule, red-brown to golden brown, 0.4-0.5 × 0.2-0.3 mm, smooth, highly glossy. 2n = 18.

Flowering late summer-fall. Moist sandy soils, river bottoms, fields, edges of intermittent pools; 0-500 m; Ariz., Ark., Calif., La., Okla., Tex.; Mexico; West Indies; South America.

Glinus radiatus is considered native to tropical and subtropical areas in the New World, although it is doubtfully native in North America. While it is unclear whether the species is native in Louisiana, where it is most common, it is undoubtedly introduced in Arizona (M. A. Lane and D. J. Keil 1976) and California (M. H. Grayum and D. L. Koutnik 1982). In Louisiana, Glinus radiatus occurs in the same habitat as G. lotoides, and the two species grow together in some populations. Some evidence of intermediates in those populations indicates hybrids may form between the two species, but this needs further investigation. Glinus radiatus and G. lotoides are most easily distinguished by seed characteristics (J. W. Thieret 1966b).

STEMS: to 35 em long. LEAVES to 20 mm long, to 12 mm wide.

FLOWERS: mostly 4-10 per cluster, the pedicels to 2 mm long; sepals 4-5(-6) mm long, the apex attenuate or long-acuminate.

SEEDS: ca. 0.4-0.5 mm long, red-brown, smooth but visibly reticulate with a cross-hatched pattern. 2n = 18, 36.

NOTES: Disturbed areas, often associated with stock tanks: Cochise, Gila, Maricopa, Pima, Santa Cruz, Yuma cos.; 250-1200 m (900-4000 ft.); May-Oct; CA, LA, OK, TX, s to CArner., W. Ind. First collected in Arizona in 1975 (Lane, M. A. and D. J. Keil. 1976. Madrofio 23:457).

REFERENCES: Christy, Charlotte M. 1998. Molluginaceae. J. Ariz. - Nev. Acad. Sci. 30(2): 112..

FNA 2004, Christy 1998, Jepson 2012

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Spreading, prostrate annual herbs, stems branching from the base, to 50 cm long; herbage with forked or stellate hairs.

Leaves: Whorled to alternate, on petioles 1-7 mm long; blades obovate to elliptic, 5-25 mm long and to 12 mm wide, with tapered bases, broadly rounded to acute tips, and entire to toothed margins; surfaces green to gray-green; stipules absent.

Flowers: Clustered mounds of 3-15 pyramidal, flask- or bell-shaped flowers bourne in leaf axils; flowers dusty brownish pink, tomentose with whitish hairs, especially near the bases and lower portions; petals absent; sepals 5, fused basally, with attenuate or long-acuminate tips and wide, scarious margins; stamens 3-20, free or fused in groups, the outer sterile; styles absent or short; stigmas 3-5.

Fruits: Capsules ellipsoid, 3 mm long, 3-5-valved, included in calyx; seeds many, minute, reniform to lenticular, 0.5 mm, reddish or golden brown, surfaces smooth but visibly reticulate with a cross-hatched pattern and an aril coiled around each seed.

Ecology: Found on moist sandy soils in disturbed areas; often associated with stock tanks, wetted or seasonally dry margins of wetlands, river bottoms, fields, and edges of intermittent pools, from 900-4,000 ft (274-1219 m); flowering June-September.

Distribution: Arizona, Arkansas, California, Louisiana, Oklahoma, Texas; Mexico.

Notes: This species is native to the New World tropics, and FNA notes it is likely introduced in Arizona. First collected in AZ in 1975, this disturbance-adapted weed is relatively rare and most often associated with stock tanks. Its congener, G. lotoides, is even more rare in Arizona, known only from one stock tank at Cabeza Prieta Wildlife Refuge. The two species are best distunguished by their seeds, with G. radiatus having reticulate seeds with arils (white appendages), and G. lotoides having tuberculate seeds that lack arils. G. radiatus superficially resembles some other, more common prostrate desert weeds such as Boerhavia coccinea and Trianthema portulacastrum. Look for the stellate hairs that cover the leaves, stems, flowers, and capsules on G. radiatus, as well as the flowers in dusty pink-colored custers.

Ethnobotany: Unknown, but other species in the genus have uses.

Synonyms: Glinus cambessedessii, Mollugo cambessedesii, Mollugo radiata

Editor: LCrumbacher 2012, AHazelton 2015

Etymology: Glinus is Greek for "sweet juice," as glinos and glinon were names used by Theophrastus and Pliny for a maple tree, or plant with sweet sap; radiatus likely means spreading out from a central point, referring to the spreading prostrate growth form of this species.