The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

anglestem primrose-willow, anglestem waterprimrose

narrowleaf primrose-willow

Habit Herbs, perennial or (robust) annual, or shrubs, often with woody base, when aquatic, forming white pneumatophores from nodes. Herbs slender, usually with aerenchyma near base, forming stolons 10–30 cm, 0.8–2.5 mm thick.
Stems

usually erect or strongly ascending, rarely floating or creeping, terete to somewhat angled on young branches, 30–250 cm, well branched to sparsely branched or simple, usually villous, often also strigillose, rarely glabrous, with raised lines decurrent from leaf axils.

erect, slightly ridged, often well branched, (22–)50–100(–145) cm, glabrous or sparsely to densely, minutely strigillose.

Leaves

stipules narrowly deltate, 0.1–0.2 × 0.1–0.2 mm;

petiole 0.2–3.5 cm;

blade broadly lanceolate, 3.5–18 × 1–4 cm, base narrowly cuneate, margins subentire, apex acuminate, surfaces hirsute or villous;

bracts slightly to much reduced.

alternate;

stipules narrowly ovate or lanceolate, 0.15–0.3 × 0.05–0.15 mm;

stolons: petiole attenuate, 0.2–0.5 cm, blade narrowly to very narrowly elliptic, 1–2.5 × 0.3–0.9 cm, surfaces glabrous or minutely strigillose;

stems: subsessile, blade linear to elliptic-linear, 1.6–6(–8.5) × 0.1–0.4(–0.6) cm, base very narrowly cuneate, margins entire with obscure hydathodal glands, apex very narrowly acute, surfaces glabrous or sparsely to densely, minutely strigillose or puberulent;

bracts not much reduced.

Inflorescences

leafy racemes, flowers solitary in axils;

bracteoles often absent, when present, narrowly deltate, 2–3 × 1.2–2.4 mm, attached near ovary base.

leafy racemes or spikes, flowers solitary in leaf axils;

bracteoles deciduous, attached on pedicel near ovary base or to 4.5 mm distal to base, linear, 0.4–4(–7.5) × 0.1–0.3 mm.

Flowers

sepals ovate-deltate, 5.5–11 × 1.5–3 mm, margins entire, apex acuminate, surfaces villous;

petals orange-yellow, obovate, 5–11 × 4–8 mm;

stamens (8 or)10 or 12(or 14), in 2 unequal series, longer filaments 2.5–4.5 mm, shorter ones 1.5–2.5 mm, anthers oblong, 1.2–1.6 × 0.7–1 mm, extrorse;

ovary cylindric, subterete, 10–16 × 2–3 mm, glabrate to strigillose or villous;

nectary disc slightly elevated at ovary apex, 2–4 mm diam., lobed, depressed, surrounded by densely matted white hairs;

style 3–4.5 mm, glabrous, stigma capitate-globose, 1–1.5 × 2–2.5 mm, ± exserted beyond anthers.

sepals ascending, green, lanceolate-deltate to narrowly so, 2.5–5(–5.5) × 1–3(–3.5) mm, margins entire, apex acuminate or elongate-acuminate to cuspidate, surfaces sparsely to densely strigillose;

petals obovate to suborbiculate, 3–6 × (2–)2.5–5 mm, base attenuate, margins entire, apex obtuse;

filaments white or cream, 1.1–2.2 mm, anthers lanceolate-oblong, 1–2 × 0.6–1 mm;

pollen shed in tetrads;

ovary cylindric (wider at apex), 2.5–4.5 ×1–2.5 mm, strigillose;

nectary disc elevated (0.2–)0.3–0.6 mm on ovary apex, yellow, 1.3–2.5 mm diam., 4-lobed, margins glabrous or minutely strigillose;

style yellowish green, (0.4–)0.7–1.5 mm, glabrous or densely strigillose on proximal part, stigma clavate to subcapitate, (0.6–)1–1.9 × 0.6–0.9 mm, shallowly 4-lobed, not exserted beyond anthers.

Capsules

obscurely [4 or]5 or 6[or 7]-angled or subterete, straight or curved, 15–50 × 2.5–4 mm, relatively thin-walled, seeds visible as bumps, tardily and irregularly loculicidal, villous, pedicel 2–20 mm.

elongate-obpyramidal, obscurely 4-angled, often with central, longitudinal groove on each side, 5–10(–12) × 2–5.5 mm, hard-walled, dehiscent by apical ring, pedicel 0–3.5(–5) mm.

Seeds

in 1 row per locule, horizontal and loosely embedded in an easily detached horseshoe-shaped segment of firm endocarp, pale brown, obovoid, 1–1.2 mm, shiny, finely pitted, raphe much narrower than seed body.

light brown, oblong-elliptic,0.5–0.7 × 0.2–0.3 mm, surface cells oblong, elongate either parallel or transversely to seed length.

2n

= 32, 48.

= 16.

Ludwigia leptocarpa

Ludwigia linearis

Phenology Flowering summer. Flowering late Jun–Sep.
Habitat Wet places, mainly along coastal areas, especially ditches, banks near brackish water. Drainage ditches, along river or stream banks, swales, edges of pocosins, sandy soil in wet meadows, brackish marshes, disturbed ground.
Elevation 0–200[–1300] m. (0–700[–4300] ft.) 0–300 m. (0–1000 ft.)
Distribution
from FNA
AL; AR; DE; FL; GA; IL; IN; KY; LA; MD; MO; MS; NC; OH; OK; PA; SC; TN; TX; VA; WV; Central America; South America; Mexico (Campeche, Chiapas, Jalisco, Nayarit, Oaxaca, San Luis Potosí, Tabasco, Tamaulipas, Veracruz); West Indies (Cuba, Hispaniola, Jamaica, Puerto Rico); Africa; Indian Ocean Islands (Madagascar)
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; DE; FL; GA; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
[WildflowerSearch map]
[BONAP county map]
Discussion

Ludwigia leptocarpa is a globally widespread and morphologically variable species; in the flora area it is distributed widely in wet areas of the southeastern United States. Both tetraploid and hexaploid plants are known, but it is not clear if or how ploidy level is related to the considerable morphological variation, especially in pubescence type and pattern.

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

Ludwigia linearis is widespread in the southeastern United States, with a complex pattern of morphological variation, especially in stem pubescence, ranging from glabrous to densely strigillose, but without strong geographical separation (C. I. Peng 1989).

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

Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Seminudae 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. lanceolata, 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. 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
Synonyms Jussiaea leptocarpa, J. biacuminata, J. foliosa, J. leptocarpa subsp. angustissima, J. leptocarpa var. angustissima, J. leptocarpa var. meyeriana, J. pilosa, J. pilosa var. robustior, J. schottii, J. surinamensis, J. variabilis, J. variabilis var. meyeriana, J. variabilis var. pilosa, L. leptocarpa var. angustissima, L. leptocarpa var. meyeriana Isnardia linearis, L. angustifolia, L. linearis var. puberula
Name authority (Nuttall) H. Hara: J. Jap. Bot. 28: 292. (1953) Walter: Fl. Carol., 89. (1788)
Web links