Integrative Biology 260:
Systematics of Plants
Families of the Caryophyllales:
Polygonaceae
Readings:
Judd et al. 3rd edition, Plant Systematics: A Phylogenetic Approach (p. 334 – 335)
Other Resources:
Digital Flowers: Polygonaceae
Polygonaceae
(Buckwheat Family)
Habit:
- Distribution
- Annual or perennial herbs, sometimes shrubs or even trees in the tropics
- Anthocyanin pigments produced
Rumex:
Coccoloba:
- 
Polygonum:
Leaves:
- Alternate, seldom opposite, whorled, or basal; entire
- Stipules present and sheathing around stem (OCREA)
Polygonum:
Rumex:
Flowers:
- Perfect or rarely imperfect, actinomorphic
- Sepals often in 2 whorls of 3, distinct or connate at the base, sometimes with an inner sepal fused with an outer one
- Petals absent
- Carpels 2-3, syncarpous
- Ovary superior, 1-locular with 1 basal ovule
Polygonum: (5 sepals)
Rheum: (3+3 sepals)
Inflorescence:
- Mostly racemes, spikes, or panicles
- Sometimes in small axillary clusters
Polygonum inflorescences:
Fruits:
- Achenes, triangular [3 carpels] or lens-shaped [2 carpels] in X.S.
- Embryo peripheral, often S-shaped
Polygonum:
Polygonaceae Class Notes
Polygonaceae illustration from Zomlefer, page 87
Polygonaceae illustration from Judd et al., page 335
Examples:
Coccoloba uvifera (seaside grape)
Another plant of Coccoloba uvifera; the person is Richard A. Howard, late director of the Arnold Arbortum, who was an expert on this genus.
Fagopyrum esculentum (buckwheat)
Polygonum (knotweeds, smartweeds)
Rheum rhaponticum (rhubarb)
Rumex (dock)
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