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Polygonum ramosissimum subsp. ramosissimum

Higher Taxonomy
Family: PolygonaceaeView DescriptionDichotomous Key

Habit: Annual to shrub [tree]. Stem: nodes swollen or not. Leaf: simple, basal or cauline, generally alternate; ocreae present or 0, generally scarious, persistent or not. Inflorescence: flower clusters in axillary to terminal cyme-, panicle-, raceme-, spike-, umbel- or head-like arrangements, entire inflorescence or main inflorescence branches generally subtended by bracts ("inflorescence bracts"); peduncles present or 0; flower clusters in Eriogoneae-Eriogonoideae subtended by involucre of >= 1 free or +- fused, sometimes awn-tipped bracts ("involucre bracts") or, in Polygonoideae and rarely in Eriogonoideae, not (if bracts completely fused, involucre "tubular"); pedicels in Eriogoneae each often subtended by 2 free, transparent, linear bractlets or in Polygonoideae all subtended by 2+ fused, membranous, wide bractlets. Flower: generally bisexual, small, 1--200 per node; perianth parts 2--6, generally in 2 whorls, free or basally fused, generally petal-like, often +- concave adaxially, often darker at midvein, often turning +- red or +- brown in age; stamens [1]3 or 6--9 in 2 whorls; ovary superior, 1-chambered, ovule 1, styles 1--3. Fruit: achenes, included in or exserted from perianth, generally 3-angled, ovoid or elliptic, generally glabrous.
Genera In Family: 48 genera, +- 1200 species: worldwide, especially northern temperate; some cultivated for food (Coccoloba, sea-grape; Fagopyrum, Rheum, Rumex) or ornamental (Antigonon, lovechain; Coccoloba; Muehlenbeckia; Persicaria; Polygonum), a few timbered (Coccoloba; Triplaris). Several (Emex; Fallopia; Persicaria; Polygonum; Rumex) are weeds. Note: Treatment of genera in Eriogonoideae based on monographic work of James L. Reveal. Involucre number throughout is number (1--many) per ultimate grouping, at tips of ultimate branches; flower number is per flower cluster or involucre, unless otherwise stated. Fagopyrum esculentum Moench not naturalized, considered an historical waif (or garden weed +- presently), therefore not treated.
eFlora Treatment Author: Mihai Costea, except as noted
Genus: PolygonumView DescriptionDichotomous Key

Common Name: KNOTWEED
Habit: Annual, perennial herb to shrub. Stem: prostrate to erect, 8--16-ribbed or 4--5-angled with ribs 0 or obscure; glabrous or papillate-scabrous. Leaf: cauline, alternate, petioled or not; ocrea generally jointed to leaf, generally cylindric proximally, generally translucent distally, white or silvery, 2-lobed, glabrous, disintegrating to fibers or completely; blade linear, lanceolate, elliptic, ovate, or subround, entire. Inflorescence: axillary, terminal, generally spike-like; peduncle 0; pedicels present or 0, included in to exserted from bractlets; flowers 1--7(10). Flower: bisexual, base not stalk-like; perianth not enlarging, bell- to urn-shaped, glabrous, white or green-white to pink; perianth parts 5, fused 3--60[70]%, petal- or sepal-like, similar [or not], outer +- keeled or not, < to > inner, midveins generally a different shade or color than rest of perianth; stamens 3--8 (some staminodes or not), filaments or at least innermost free, wider at base, fused to perianth tube or not, anthers elliptic to oblong, white-yellow or generally pink to purple (orange-pink); styles (2)3, generally spreading, free or fused basally, stigmas 2--3, head-like. Fruit: included or exserted, wings 0, angles (2)3, 1 face much narrower than other (1)2 or not; tip beak-like, yellow-green, brown, or black. Seed: embryo curved.
Species In Genus: +- 65 species: +- worldwide; sect. Duravia restricted to western North America. Etymology: (Greek: poly, many, gony, knee joint, or gone, seed, of uncertain meaning) Note: Many species of sect. Polygonum with 2 kinds of fruit, differing in germination and morphology (summer fruit brown, ovate, tubercled to smooth; late-season fruit olive-green, lanceolate, smooth, 2--5 × > summer), but of little taxonomic importance. Mature, early-season plants with leaves, flowers, fruits needed for identification. Flowers "closed" or "1/2-open" should be determined on herbarium specimens. Other taxa in TJM (1993) moved to Aconogonon, Bistorta, Fallopia, Persicaria.
Species: Polygonum ramosissimumView Description 

Habit: Annual. Stem: erect, 10--100(200) cm, glabrous, green, ribbed, branches generally profuse in distal 1/2. Leaf: proximal often early-deciduous, distal < to >> flowers; ocreae 6--12(15) mm, proximally cylindric, distally soon disintegrating to brown fibers; petiole 2--4 mm; blade 8--70 mm, 4--18(35) mm wide, narrowly elliptic, lanceolate, or oblanceolate (ovate), light-yellow-green to -blue-green, margins flat, tip acute to acuminate or obtuse. Inflorescence: axillary, terminal, spike-like; pedicels included or exserted, 1--6 mm; flowers 2--5, crowded distally or not. Flower: closed; perianth (2)2.2--3.6(4) mm, green-yellow, margin green-yellow to yellow or white to pink, tube 20--38% of length, lobes overlapped, not keeled, elliptic to oblong, hood-shaped, midvein thickened or not; stamens 3--6(8). Fruit: included or exserted, 1.6--3.5 mm, ovate, dark-brown, shiny or dull, rough to generally smooth; late-season common, 4--15 mm. Chromosomes: 2n=60.
Note: An unnamed variant of Polygonum ramosissimum in saline marshes in SnFrB mistakenly identified as Polygonum patulum M. Bieb., may be taxonomically significant; study needed.

Polygonum ramosissimum NULL subsp. ramosissimum
Habit: Plant generally yellow-green fresh or dry. Stem: 30--200 cm. Leaf: distal 1--2 mm, < flowers, or 5--15 mm, >> flowers; blade 35--70 mm, 7--18(35) mm wide, narrowly elliptic to lanceolate (ovate), tip acute to acuminate; stem leaves 2.1--3.5(4.2) × branch leaves. Inflorescence: axillary, terminal, spike-like; pedicels exserted, 2.5--6 mm; flowers 2--5, crowded distally. Flower: perianth (2.6)3--4 mm, margin green-yellow, yellow (white or pink); stamens 3--6(8). Fruit: (2.3)2.5--3.5 mm, shiny or dull, smooth to rough; late-season common, 5--12 mm.
Ecology: Disturbed places, saline marshes; Elevation: < 200 m. Bioregional Distribution: n CA-FP, SnFrB; Distribution Outside California: North America. Flowering Time: Jul--Sep
Synonyms: Polygonum exsertum Small; Polygonum interior Brenckle; Polygonum latum Rydb.; Polygonum leptocarpum B.L. Rob.; Polygonum stevensii Brenckle; Polygonum triangulum E.P. Bicknell
eFlora Treatment Author: Mihai Costea
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botanical illustration including Polygonum ramosissimum subsp. ramosissimum


Citation for this treatment: Mihai Costea 2016. Polygonum ramosissimum subsp. ramosissimum, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on April 28, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on April 28, 2016.

Geographic subdivisions for Polygonum ramosissimum subsp. ramosissimum:
n CA-FP, SnFrB;
Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.