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Sium suave

Higher Taxonomy
Family: Apiaceae (Umbelliferae)View DescriptionDichotomous Key

Habit: Annual to perennial herb [shrub, tree], generally from taproot. Stem: generally +- scapose, generally ribbed, hollow. Leaf: basal and generally cauline, generally alternate; stipules generally 0; petiole base generally sheathing stem; blade generally much dissected, occasionally compound. Inflorescence: umbel or head, simple or compound, generally peduncled; bracts present in involucres or 0; bractlets generally present in "involucels". Flower: many, small, generally bisexual (or some staminate), generally radial (or outer bilateral); calyx 0 or lobes 5, small; petals 5, free, generally ovate or spoon-shaped, generally incurved at tips, generally +- ephemeral; stamens 5; pistil 1, ovary inferior, 2-chambered, generally with a +- conic, persistent projection or platform at tip subtending 2 free styles. Fruit: 2 dry, 1-seeded halves (= mericarps), separating from each other but generally +- persistent to central axis; ribs on halves 5, 2 marginal, 3 to back; oil tubes 1--several per interval between ribs.
Genera In Family: 300 genera, 3000 species: +- worldwide, especially temperate; many cultivated for food or spice (e.g., Carum, caraway; Daucus; Petroselinum); Bupleurum lancifolium Hornem. is historical garden weed; some toxic (e.g., Conium). Note: Mature fruit generally critical in identification, shape given in outline. Hydrocotyle moved to Araliaceae. Petroselinum crispum (Mill.) A.W. Hill is a waif.
eFlora Treatment Author: Lincoln Constance & Margriet Wetherwax, except as noted
Scientific Editor: Douglas H. Goldman, Bruce G. Baldwin.
Genus: SiumView Description 

Habit: Perennial herb, glabrous; roots clustered, fibrous or +- tuberous. Stem: erect or ascending, branched. Leaf: blade oblong to ovate, 1-pinnate, occasionally 2-pinnate when submerged, leaflets distinct, serrate, irregularly cut to pinnately lobed. Inflorescence: umbels compound, generally opposite a leaf; bracts, bractlets leaf-like, generally reflexed, conspicuous; rays, pedicels many, spreading-ascending. Flower: occasionally +- bilateral; calyx lobes 0 or minute; petals wide, white, narrowed at tips, outer +- > others. Fruit: ovate to round, +- compressed side-to-side; ribs prominent, +- equal, corky; oil tubes 1--3 per rib-interval; fruit axis entire or divided to base, adhering to fruit halves or not. Seed: face flat. Chromosomes: 2n=12.
Species In Genus: +- 10 species: North America, Eurasia, Africa. Etymology: (Greek: for an aquatic member of family)

Sium suave Walter
Habit: Plant 6--12 dm, stout. Leaf: petiole 1--8 dm, segmented; blade 6--25 cm, 7--18 cm wide, leaflets 1--4 cm, linear or lanceolate, serrate, irregularly cut. Inflorescence: peduncle 4--10 cm; bracts 6--10, 3--15 mm, linear or lanceolate, acute, entire to irregularly cut; bractlets 4--8, 1--3 mm, lance-linear; rays 10--20, 1.5--3 cm, +- equal, slender; pedicels 3--5 mm. Fruit: 2--3 mm wide. Chromosomes: 2n=12.
Ecology: Swamps, marshes, streambanks; Elevation: < 2350 m. Bioregional Distribution: CaRH, c SNH, deltaic GV, GB; Distribution Outside California: to British Columbia, eastern North America; eastern Asia. Flowering Time: Jul--Aug
eFlora Treatment Author: Lincoln Constance & Margriet Wetherwax
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botanical illustration including Sium suave


Citation for this treatment: Lincoln Constance & Margriet Wetherwax 2017. Sium suave, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on May 24, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on May 24, 2017.

Geographic subdivisions for Sium suave:
CaRH, c SNH, deltaic GV, GB;
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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.