5.06 LUZIOLA Juss.
Edward E. Terrell

Kunzer and Bodle (2008) reported finding a fourth species of Luziola, L. subintegra, in Florida. This treatment has been amended to reflect their discovery.

Plants perennial; aquatic, usually rooted, sometimes floating; stoloniferous, sometimes mat-forming; monoecious. Culms 10–100+ cm, erect or prostrate, sometimes rooting at the nodes, branched, emergent or immersed. Leaves cauline; sheaths open, not inflated or somewhat inflated; ligules hyaline; pseudopetioles present or absent; blades flat, linear to lanceolate or narrowly elliptic, glabrous, pubescent, or scabrous. Inflorescences panicles, racemes, or spikes, exserted or enclosed, staminate and pistillate spikelets usually in separate inflorescences, pistillate inflorescences at the lower or middle nodes, staminate inflorescences usually terminal; disarticulation below the spikelets. Spikelets unisexual, laterally compressed to subterete, with 1 floret. Glumes absent; calluses glabrous; lemmas and paleas subequal, ovate or lanceolate, membranous or hyaline, unawned; lodicules 2. Staminate lemmas and paleas obscurely few- to several-veined; anthers 6–16. Pistillate lemmas 5–14-veined, margins not clasping the margins of the paleas, unawned; paleas 3–10-veined; styles 2, bases fused, stigmas laterally or terminally exserted, plumose. Fruits achenes, ovoid, ellipsoid, or subglobose, beaked by the persistent style bases; pericarps shell-like, partially free from the seed, smooth or striate, crustaceous; seeds ovoid to subglobose; embryos basal; hila linear. x = 12. Name modified from Luzula, a genus of the Juncaceae.

Luziola is a genus of nine species that range from the southeastern United States to Argentina. Only L. fluitans is native to the Flora region; three other species have been introduced and are established. The species are emergent or immersed in shallow, fresh to brackish water. The revision by Martinez-y-Peres et al. (2008) cited below has not been incorporated into this account. It does not appear to differ in the interpretation of the four species treated here, but it does offer considerable additional information about these species and those the grow outside the United States.

SELECTED REFERENCES Anderson, L.C. and D.W. Hall. 1993. Luziola bahiensis (Poaceae): New to Florida. Sida 15:619–622; Kunzer, J.M. and M.J. Bodle. 2008. Luziola subintegra (Poaceae): Oryzeae), new to Florida and te United States. Journal of the Botanical Research Institute of Texas 2: 633-636; Martinez-y-Perez, J.L., T. Mejia-Saules, and V. Sosa. (2008), A taxonomic revision of Luziola (Poaceae: Oryzeae). Systematic botany 33:702-718; Pohl, R.W. and G. Davidse. 2001. Luziola. Pp. 2072–2073 in W.D. Stevens, C.U. Ulloa, A. Pool, and M. Montiel (eds.). Flora de Nicaragua, Vol. 3: Angiosperms (Pandanaceae–Zygophyllaceae). Missouri Botanical Garden Press, St. Louis, Missouri, U.S.A. 2666 pp. [for vols. 1–3]; Swallen, J.R. 1965. The grass genus Luziola. Ann. Missouri Bot. Gard. 52:472–475; Terrell, E.E. and H. Robinson. 1974. Luziolinae, a new subtribe of oryzoid grasses. Bull. Torrey Bot. Club 101:235–245.

 

For an interactive dichotomous key, click here; the interactive, multientry key is not yet available.

1. Culms 3-10 mm thick; blades 7-20 mm wide; ligules 10-40 mm long .....L. subintegra
1. Culms up to 2 mm thick; blades up to 6 mm wide; ligules less than 6 mm long ... 2
2 . Culms prostrate, usually immersed; leaves floating or streaming in currents, 1–5(8) cm long, usually more numerous towards the ends of the culms; pistillate inflorescences mostly
included in the sheaths, only the stigmas visible ... L. fluitans
2. Culms suberect to erect, from fully emergent to immersed; leaves not conspicuously floating or streaming, longer than 6 cm, basal or scattered along the culms; pistillate inflorescences all or mostly exserted, their branches and spikelets evident ... 3
3. Pistillate florets 3–5 mm long; achenes striate ... L. bahiensis
3. Pistillate florets 2–2.5 mm long; achenes smooth ... L. peruviana

1. Luziola subintegra Swallen

Plants perennial; aquatic, floating or emergent; stoloniferous, mat-forming or prostrate creeping. Culms to 1+ m long, 3-10 mm thick, rooting at the nodes. Sheaths inflated, spongy; ligules 10-40 mm long, membranous, auriculate, acuminate; blades 10-75 cm long, 7-20 mm wide. Pistillate panicles axillary, congested, 1-several per culm, barely exerted from the sheath; primary branches shrply recurved at maturity, with evident pulvini. Pistillate spikelets 3-5.5. mm long; lemmas 5-7-veined; paleas 3-veined. Staminate panicles terminal, open. Staminate spikelets 5-7 mm; lemmas 4-5-veined, hyaline; paleas hyaline, 3-veined. Caryopses to 2 mm long; pericapr hard, brittle, minutely longitudinally triate, asymmetrically ovoid; style bases persistent.

Luziola subintegra is native from Mexico, Central America, and the Caribeean Basin, extending south through South America to Argentina. Kunzer and Bodle reported its discovery from Lake Okeechobee, Glades County, Florida. The above description is taken from their paper, which also provides illustrations of the species.

2. Luziola fluitans (Michx.) Terrell & H. Rob.
Silverleaf Grass, Watergrass

Plants stoloniferous; mostly immersed. Culms to 1+ m long, to 2 mm thick; bases prostrate and rooting at the nodes. Leaves mainly cauline, usually crowded distally, streaming in the current or floating on the surface, distal leaves sometimes emergent; sheaths glabrous; ligules 0.5–2 mm, subtriangular to truncate, sometimes erose; pseudopetioles sometimes present; blades 1–5(8) cm long, 1–4 mm wide, glabrous, sometimes pilose basally, scabridulous. Inflorescences spikes or racemes, spikelets sessile or shortly pedicellate. Staminate inflorescences 1–2 cm, terminal, partially exserted from the sheaths, emergent at anthesis, with 2–4 spikelets; staminate florets 3–5 mm; lemmas narrowly ovate, usually 5-veined; paleas similar, usually 3-veined; anthers 6, 2–3.7 mm, linear. Pistillate inflorescences 0.5–2 cm, mostly included in the subtending sheaths, only the stigmas visible, with 2 to few spikelets; pistillate florets 1.4–3 mm, caducous; lemmas 5–9-veined, acuminate; paleas similar to the lemmas, 3–7-veined; stigmas 3–6 mm. Achenes 1.3–2 mm, ovoid, asymmetrical, minutely striate, lustrous. 2n = 24.

Luziola fluitans grows in fresh to slightly saline lakes and streams in the southeastern United States and eastern Mexico. It is most common in the coastal plain, and also occurs in the Piedmont. Plants in the United States and eastern Mexico belong to L. fluitans (Michx.) Terrell & H. Rob var. fluitans, which differs from L. fluitans var. oconnorii (R. Guzmán) G. Tucker of the uplands of central Mexico in having shorter and narrower leaf blades, shorter spikelets, and shorter anthers.

 

3. Luziola bahiensis (Steud.) Hitchc.
Brazilian Watergrass

Plants stoloniferous, emergent or immersed. Culms 10–50 cm, suberect to erect. Leaves mostly basal or scattered along the culms, not conspicuously float-ing or streaming in the current; sheaths glabrous or ciliate; ligules to about 6 mm, lanceolate, acuminate; pseudopetioles sometimes present; blades 3–30(39) cm long, 1–6 mm wide, glabrous or puberulent. Inflorescences panicles; pedicels capillary. Staminate panicles 4–6 cm, terminal, with 9–17 spikelets; staminate florets 4–8 mm; lemmas lanceolate, faintly 5–9-veined; paleas similar, 3-veined; anthers 6, 2–4 mm, linear. Pistillate panicles to about 12 cm, arising from the lower nodes of the culms, all or mostly exserted, with 9–17 spikelets; branches slender, divergent to reflexed; pistillate florets 3–5 mm, caducous; lemmas 8–13-veined, acuminate or caudate; paleas similar, 6–8-veined; stigmas 2–4 mm. Achenes 1.5–2.2 mm, ovoid or broadly ellipsoid, lightly to moderately striate, somewhat lustrous. 2n = 24.

Luziola bahiensis is native from the Caribbean south to Argentina. It has been found at scattered locations in southern Louisiana, Mississippi, Alabama, and north-western Florida. It grows in wet places or shallow water along streams and lakes.

 

4. Luziola peruviana J.F. Gmel.
Peruvian Watergrass

Plants stoloniferous, fully or mostly emergent. Culms 10–40 cm, suberect, branching, fully or mostly emergent. Leaves mostly basal or scattered along the culms, not conspicuously floating or streaming in the current; sheaths glabrous or ciliate; ligules to 5 mm, lanceolate, acuminate; blades 3–30 cm long, 0.5–4 mm wide, glabrous, sometimes scabridulous. Inflorescences panicles. Staminate panicles 1–3 cm, terminal, with 10–25 spikelets; staminate florets 3.5–8 mm, caducous; lemmas lanceolate, 5-veined; paleas similar, 3-veined; anthers 6, 2–5 mm. Pistillate panicles to 7 cm, arising from the lower to middle nodes of the culms, partially exserted from the sheaths, with 10–25 spikelets; branches filiform, spreading to reflexed; pistillate florets 2–2.5 mm, caducous; lemmas 7–14-veined, erose to acuminate or caudate; paleas similar to the lemmas, 5–10-veined; stigmas 2–3 mm. Achenes 1–1.3 mm, broadly ellipsoid to subglobose, smooth, lustrous. 2n = 24.

Luziola peruviana has been found at scattered locations from Texas to Florida. It is native to the Caribbean, Central America, and South America, and grows in wet places and shallow water along streams and lakes.