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

smallfruit primrose-willow

Habit Herbs, perennial or (robust) annual, or shrubs, often with woody base, when aquatic, forming white pneumatophores from nodes. Herbs slender, sometimes suffrutescent from woody base, often with aerenchyma, rarely creeping and rooting at nodes, often forming slender stolons 4–15(–25) cm, 0.4–0.8 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.

usually erect or ascending, rarely prostrate, slightly to distinctly winged, wings to 1.8 mm wide, unbranched to densely branched, 5–60 cm, glabrous.

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 lanceolate-deltate, 0.13–0.15 × 0.1–0.13 mm;

stolons: petiole attenuate, 0.1–0.5 cm, blade broadly elliptic to suborbiculate, 0.2–0.7 × 0.2–0.5 cm;

stems: petiole winged, 0.1–0.5 cm, blade obovate-spatulate or oblanceolate, sometimes narrowly oblanceolate-elliptic, 0.4–1.7 × 0.15–1 cm, base attenuate, margins subentire or often with hydathodal glands forming minute teeth, or minutely papillose-strigillose, apex acute or mucronate, surfaces glabrous;

leaves on side branches much reduced, glabrous;

bracts near apex and on branches 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 spikes or racemes, flowers solitary in axils, usually not crowded;

bracteoles attached at base of ovary, sublinear or narrowly oblong, 0.4–1.2(–1.5) × 0.1–0.4 mm, usually with swollen base.

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 or spreading, pale green to cream adaxially, ovate-deltate, 0.9–2 × 1–1.9 mm, margins minutely papillose-strigillose or entire, apex acuminate, surfaces glabrous;

petals 0;

filaments translucent, 0.4–0.55 mm, anthers 0.1–0.2 × 0.2–0.3 mm;

pollen shed singly;

ovary pale green, obovoid-subglobose, 0.8–1 × 0.8–1.2 mm, glabrate;

nectary disc nearly flat on ovary apex, light green, 0.5–1.2 mm diam., 4-lobed, glabrous;

style light green, 0.3–0.6 mm, glabrous, stigma subcapitate, 0.15–0.3 × 0.05–0.15 mm, 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.

obconic, subterete, 1–1.5 × 1.4–1.9 mm, thin-walled, seeds often visible as bumps, dehiscent by apical ring, pedicel 0–0.2 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.

dark reddish brown, oblong-ovoid, 0.5–0.6 × 0.3–0.4 mm, surface cells transversely elongate, glabrous or, sometimes, densely covered by waxy hairs.

2n

= 32, 48.

= 16.

Ludwigia leptocarpa

Ludwigia microcarpa

Phenology Flowering summer. Flowering Mar–Nov (year-round).
Habitat Wet places, mainly along coastal areas, especially ditches, banks near brackish water. Roadside ditches, marshes, borders of ponds and streams, low meadows, low areas in open woods, edges of swamp forests, brackish marshes, hammocks, solution pits of limestone on marl prairies.
Elevation 0–200[–1300] m. (0–700[–4300] ft.) 0–400 m. (0–1300 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; FL; GA; LA; MO; MS; NC; SC; TN; TX; VA; West Indies (Bahamas, Cuba, Jamaica)
[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.)

The diploid Ludwigia microcarpa has the smallest stature, leaves, flowers, fruits, and fewest seeds (ca. 10–20) per capsule of any species in sect. Isnardia (C. I. Peng 1989). Most plants start to flower when young.

(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. linearis, L. linifolia, L. maritima, 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 microcarpa
Name authority (Nuttall) H. Hara: J. Jap. Bot. 28: 292. (1953) Michaux: Fl. Bor.-Amer. 1: 88. (1803)
Web links