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Ludwigia affinis

Interesting Facts

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Description

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Family Onagraceae

Annual or perennial herbs, or shrubs , rarely trees to 30 m tall, often with epidermal oil cells , usually with internal phloem . Leaves simple , spirally arranged , opposite, or occasionally whorled , entire or toothed to pinnatifid ; stipules present and usually caducous , or absent. Flowers perfect and hermaphroditic or occasionally unisexual , actinomorphic or zygomorphic, (2-) 4(-7) -merous, axillary , in leafy spikes or racemes or solitary, or occasionally in panicles, all but Ludwigia with distinct floral tube , nectariferous within. Sepals green or colored , valvate . Petals as many as sepals or rarely absent, variously colored, imbricate or convolute and occasionally clawed. Stamens as many as sepals in one series or 2 × as many as sepals in 2 series [in Lopezia Cavanilles reduced to 2 or 1 plus 1 sterile staminode]; anthers versatile or basifixed , dithecal , sometimes cross-partitioned, opening by longitudinal slits; pollen grains almost always united by viscin threads, shed as monads , tetrads , or polyads . Ovary inferior, with as many carpels and locules as sepals, septa sometimes thin or absent at maturity; placentation axile or parietal , ovules 1 to many per locule, in 1 or several rows or clustered, anatropous , bitegmic; style 1; stigma with as many lobes as sepals or clavate to globose . Fruit a loculicidal capsule or indehiscent nut or berry. Seeds small, smooth or variously sculptured , sometimes with a coma [or wing ], with straight oily embryo, endosperm lacking.

Seventeen genera and ca. 650 species: widespread in temperate and subtropical areas, but best represented in W North America; six genera (two introduced ), 64 species (11 endemic, 11 introduced), and five natural hybrids (two endemic) in China.

Onagraceae are a well-defined, monophyletic family in the order Myrtales, with a sister relationship to Lythraceae. Within the order Myrtales, the Onagraceae are distinguished by a number of features including (1) a distinctive 4-nucleate embryo sac; (2) abundant raphides in vegetative cells ; (3) paracrystalline beaded pollen ektexine; and (4) pollen with viscin threads.

Some species of Oenothera are grown for the oil in their seeds, which contains gamma linolenic acid (GLA), used for medicinal purposes. Several species of Onagraceae also are cultivated in China for their horticultural value, including species of Fuchsia Linnaeus (generally distinguished by having large, tubular , red or orange flowers and fleshy berries ) and Clarkia Pursh (distinguished by having stigmas with commissural lobes with dry, unicellular papillae, and dry, elongate capsules similar to those of Epilobium but lacking comas on the seeds) . The most commonly cultivated Fuchsia is F. ×hybrida Hort. and the related F. magellanica Lamarck in F. sect. Quelusia (Vandelli) Candolle from South America; F. triphylla Linnaeus, in F. sect. Fuchsia, from Hispaniola, is known from only one gathering in Fujian. Similarly, Clarkia amoena (Lehmann) A. Nelson & J. F. Macbride is widely cultivated in China, whereas C. pulchella Pursh is known from only one gathering in Xizang; both species are native to W North America. There are no naturalized species of either Clarkia or Fuchsia in China.[1]

Genus Ludwigia

Herbs slender, erect to prostrate and rooting at nodes, or shrubs or rarely small trees ; underwater parts often swollen and spongy or with inflated white spongy pneumatophores. Leaves alternate [or opposite], usually entire; stipules present, reduced and/or deciduous; bracteoles 2, at or near base of ovary, or absent. Flowers perfect , actinomorphic , in upper leaf axils or in spikes, racemes , or clusters ; floral tube not prolonged beyond ovary. Sepals (3 or) 4 or 5(-7), green, persistent after anthesis . Petals as many as sepals or absent, yellow or white, caducous . Stamens as many as or 2 × as many as sepals; anthers versatile or sometimes basifixed ; pollen shed singly or in tetrads or polyads . Ovary with as many locules as sepals, rarely more, apex flat or conic, often with a depressed nectary surrounding base of each epipetalous stamen; stigma capitate or hemispheric , entire or lobed , upper 1/2-2/3 receptive. Fruit an obovoid to cylindric capsule, dehiscent irregularly or by a terminal pore or by flaps separating from valvelike apex. Seeds numerous , in one to several rows per locule, free or embedded in powdery or woody endocarp, raphe small or conspicuous , sometimes equal in size to body of seed. 2n = 16, 32, 48, 64, 80, 96, 128.

Eighty-two species: cosmopolitan , on all continents except Antarctica; nine species (one endemic) in China.

Ludwigia is distinctive within the family , and morphological, anatomical, and molecular evidence indicates that it is the sister group to the remainder of the family. Historically, plants of this affinity with stamen number equal to sepal number were Ludwigia, and those with stamens twice as many as sepals were Jussiaea, but Raven and others demonstrated reticulate variation in this character, and treated the two groups as a single genus. Polyploidy and autogamy are important evolutionary phenomena within the genus.[2]

Habitat

Typically found at an altitude of 0 to 3,051 meters (0 to 10,010 feet).[3]

Taxonomy

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Synonyms

Ludwigia affinis< /i> (Dc.)

Notes

Publishing author : H.Hara Publication : J. Jap. Bot. 28: 291 1953

Basionym author: (DC.)

Similar Species

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Members of the genus Ludwigia

ZipcodeZoo has pages for 51 species, subspecies, varieties, forms, and cultivars in this genus:

L. alata (Winged Primrose Willow) · L. alternifolia (Bushy Seedbox) · L. arcuata (Piedmont Primrose-Willow) · L. bonariensis (Carolina Primrose-Willow) · L. brevipes (Long Beach Primrose-Willow) · L. curtissii (Curtiss' Primrose-Willow) · L. decurrens (Primrose Willow) · L. erecta (Yerba De Jicotea) · L. glandulosa (Creeping Seedbox) · L. glandulosa brachycarpa (Creeping Seedbox) · L. glandulosa glandulosa (Creeping Seedbox) · L. glandulosa subsp. brachycarpa (Cylindricfruit Primrose-Willow) · L. hirtella (Hairy Ludwigia) · L. hyssopifolia (Seed Box) · L. hyssopifolia apud (Seedbox) · L. lacustris (Lake Ludwigia) · L. lanceolata (Lance-Leaf Seedbox) · L. leptocarpa (Angle-Stemmed Primrose-Willow) · L. linearis (Narrow-Leaf Seedbox) · L. linifolia (Southeastern Primrose-Willow) · L. longifolia (Longleaf Primrose-Willow) · L. maritima (Seaside Primrose-Willow) · L. microcarpa (Small-Fruit Seedbox) · L. nervosa (Water Primrose) · L. octovalvis (Mexican Primrose Willow) · L. octovalvis octovalvis (Mexican Primrosewillow) · L. octovalvis sessiliflora (Mexican Primrose-Willow) · L. octovalvis subsp. octovalvis (Mexican Primrose-Willow) · L. octovalvis subsp. sessiliflora (Mexican Primrose-Willow) · L. palustris (Marsh Primrose-Willow) · L. palustris var. typica (Marsh Primrose-Willow) · L. peploides (Clove-Strip) · L. peploides glabrescens (Floating Primrosewillow) · L. peploides montevidensis (Floating Primrose-Willow) · L. peploides peploides (Floating Primrosewillow) · L. peploides subsp. glabrescens (Floating Primrose-Willow) · L. peploides subsp. montevidensis (Floating Primrose-Willow) · L. peruviana (Peruvian Primrose-Willow) · L. pilosa (Hairy Primrose-Willow) · L. polycarpa (Many-Fruit False-Loosestrife) · L. ravenii (Raven's Primrose-Willow) · L. repens (Creeping Primrose Willow) · L. sedioides (Mosaic Plant) · L. sedoides (False Loosestrife) · L. simpsonii (Simpson's Primrose-Willow) · L. spathulata (Spathulate Seedbox) · L. sphaerocarpa (Globe-Fruited False-Loosestrife) · L. suffruticosa (Shrubby Primrose-Willow) · L. uruguayensis (Large-Flower Primrose-Willow) · L. virgata (Savanna Seedbox) · L. x lacustris (Lake Ludwigia)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal December 04, 2007:

Identifiers

Footnotes

  1. Jiarui Chen, Peter C. Hoch, Peter H. Raven, David E. Boufford & Warren L. Wagner "Onagraceae". in Flora of China Vol. 13 Page 274, 290, 400. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. Jiarui Chen, Peter C. Hoch & Peter H. Raven "Ludwigia". in Flora of China Vol. 13 Page 400, 401. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  3. Mean = 478.080 meters (1,568.504 feet), Standard Deviation = 703.510 based on 190 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
Last Revised: 2012-07-21