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lanceleaf primrose-willow

shrubby primrose-willow, shrubby primrose-willow or seedbox

Habit Herbs slender, with well-developed aerenchyma when base submerged, often forming stolons 10–40 cm, 2–3 mm thick, stolons with widely spaced leaves. Herbs with 1–3 rhizomes 0.6–5.5 × 0.2–0.5 mm, often branched, glabrous or densely hirtellous, sometimes also forming stolons 8–80 cm, 1.1–2.2 mm thick, branched, glabrous or sparsely to densely hirtellous.
Stems

erect, subterete or slightly ridged, well branched distally, 45–100 cm, glabrous, with raisedlines decurrent from leaf axils.

erect, slightly ridged, unbranched or slightly branched, (16–)30–90 cm, glabrous or strigillose to hirtellous, especially on distal parts.

Leaves

alternate;

stipules ovate to very broadly ovate, 0.2–0.5 ×0.1–0.3 mm, succulent;

stolons: petiole winged, 0.2–1 cm, blade orbiculate or elliptic to broadly elliptic, 0.5–2.7 × 0.6–1.2 cm, base attenuate, apex rounded to acute;

main stem: petiole winged, 0.1–0.5 cm, blade elliptic, oblanceolate, or narrowly oblanceolate to sublinear, 2–7.5 × 0.2–0.8(–1.4) cm, base narrowly cuneate, sometimes attenuate, margins entire with minute hydathodal glands, apex acute to narrowly acute, leaves on side branches much reduced;

bracts sublinear, moderately reduced.

alternate;

stipules deltate, 0.25–0.45 × 0.15–0.4 mm;

rhizomes: sessile, blades minute, appressed, and scalelike, oblate or suborbiculate, 0.3–0.6 × 0.6–0.9 mm;

stolons: petiole 0.1–0.6 cm, blade oblong or oblanceolate-elliptic to spatulate, 0.4–3.5 × 0.2–1.5 cm;

main stem: sessile, blade lanceolate-elliptic or lanceolate-linear to linear, 2.5–9.5 × (0.1–)0.3–0.9 cm, proximal ones shorter and often oblong or oblong-lanceolate, base rounded or obtuse, margins entire with obscure hydathodal glands, apex acuminate to acute, surfaces glabrous or, sometimes, pilose on proximal blades;

bracts very reduced.

Inflorescences

open spikes, flowers solitary in distal leaf axils;

bracteoles attached in opposite pairs at or slightly distal to base of ovary, ovate-elliptic to very narrowly elliptic, 1.5–4.3 × 0.4–1.4 mm, often with a swollen base, margins minutely papillose, apex subacute.

densely clustered, terminal racemes or spikes, 1–5(–12) cm;

bracteoles attached at base of ovary or on pedicel distally, narrowly lanceolate, 3.5–5(–6) × (1.2–)1.4–2 mm, surfaces usually glabrous, sometimes pilose abaxially.

Flowers

sepals ascending, pale green, broadly ovate-deltate, 1.5–2.5 × 1.8–3.3 mm, margins minutely papillose, apex usually acute, rarely acuminate, surfaces glabrous;

petals 0;

filaments nearly translucent, 1–1.4 mm, base dilated, anthers 0.4–0.6(–0.8) × 0.5–0.6 mm;

pollen shed in tetrads;

ovary broadly obovoid or cup-shaped, 2.5–3.5 × 2.2–3.2 mm;

nectary disc elevated 0.4–0.6 mm on ovary apex, yellowish green, 1.8–2.6 mm diam., 4-lobed, glabrous;

style yellowish green, 0.5–0.7 mm, glabrous, stigma yellowish green, broadly capitate to subglobose, 0.3–0.5 × 0.7–1 mm, not exserted beyond anthers.

sepals ascending, pale green or white adaxially, broadly ovate-deltate, 2.3–3.5(–4) × 2.3–3.2(–3.8) mm, margins entire, apex acuminate, surfaces glabrous;

petals 0;

filaments yellow or cream, 1.2–2 mm, distinctly dilated toward base, anthers 0.7–1(–1.3) × 0.5–0.7 mm;

pollen shed in tetrads;

ovary broadly obovoid or cup-shaped, 2.2–3 × 2.3–3.3 mm;

nectary disc elevated 0.5–0.6 mm on ovary apex, pale yellow, 1.8–3.1 mm diam., obscurely 4-lobed, glabrous;

style pale yellow, 0.9–1.7 mm, glabrous, stigma pale green to white, globose to capitate, 0.4–0.8 × 0.5–0.8 mm, distinctly 4-lobed, not exserted beyond anthers.

Capsules

obpyramidal, sharply 4-angled and 4-winged, wings 0.3–0.7mm wide, 3.5–5 × 2.5–4.5 mm, hard-walled, dehiscent by apical ring, pedicel 0.1–0.5 mm.

broadly obpyramidal, angles rounded, sometimes subspherical, 2.5–4.3 ×2.5–4.5(–5) mm, hard-walled, dehiscent by apical ring, pedicel 0.5–1.5(–2) mm.

Seeds

light brown, narrowly oblong with constricted ends, 0.6–0.8 ×0.2–0.3 mm, surface cells nearly isodiametric.

brown, elliptic-oblong, curved on both ends, 0.5–0.6 × 0.2–0.3 mm, surface cells ± isodiametric.

2n

= 32.

= 32.

Ludwigia lanceolata

Ludwigia suffruticosa

Phenology Flowering Jun–Oct. Flowering May–Sep.
Habitat Ditches, low meadows, cypress swamps, moist pinelands, edges of pocosins, sandy peaty soil. Sandy ditches, marshes, wet meadows, limestone sinks, cypress swamps, moist pinelands.
Elevation 0–100 m. (0–300 ft.) 0–150 m. (0–500 ft.)
Distribution
from FNA
FL; GA; NC; SC
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; NC; SC
[WildflowerSearch map]
[BONAP county map]
Discussion

Ludwigia lanceolata is fairly uncommon, with scattered populations occurring along the Atlantic coast of southern North Carolina, South Carolina, eastern and southern Georgia, and peninsular Florida. It reaches its western limit in the central panhandle of Florida. C. I. Peng (1988, 1989) found this tetraploid species to be interfertile with other tetraploid species in the section, but few natural hybrids are found, perhaps due to persistent autogamy and habitat specialization.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Ludwigia suffruticosa is distinctive by virtue of its highly condensed inflorescence and sessile leaves. It also differs from other species in sect. Isnardia in that it perennates mainly by underground rhizomes. This apetalous species has showy bracts and attracts many insects, including bumblebees, wasps, and honeybees (C. I. Peng 1989). Its center of distribution is in Florida, extending along the coastal plain barely to Alabama on the west and barely to southern North Carolina on the northeast. Recent reports of this species from Mississippi and from Mexico (Chiapas and Oaxaca) have not been confirmed.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia
Sibling taxa
L. alata, L. alternifolia, L. arcuata, L. bonariensis, L. brevipes, L. curtissii, L. decurrens, L. erecta, L. glandulosa, L. grandiflora, L. hexapetala, L. hirtella, L. leptocarpa, L. linearis, L. linifolia, L. maritima, L. microcarpa, L. octovalvis, L. palustris, L. peploides, L. peruviana, L. pilosa, L. polycarpa, L. ravenii, L. repens, L. simpsonii, L. spathulata, L. sphaerocarpa, L. suffruticosa, L. virgata
L. alata, L. alternifolia, L. arcuata, L. bonariensis, L. brevipes, L. curtissii, L. decurrens, L. erecta, L. glandulosa, L. grandiflora, L. hexapetala, L. hirtella, L. lanceolata, L. leptocarpa, L. linearis, L. linifolia, L. maritima, L. microcarpa, L. octovalvis, L. palustris, L. peploides, L. peruviana, L. pilosa, L. polycarpa, L. ravenii, L. repens, L. simpsonii, L. spathulata, L. sphaerocarpa, L. virgata
Synonyms Isnardia lanceolata Isnardia suffruticosa
Name authority Elliott: Sketch Bot. S. Carolina 1: 213. (1817) Walter: Fl. Carol., 90. (1788)
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