ABSTRACT
In the following pages, readers can find their bearings from the title appearing at the top of each left hand page giving the order to which the family described belongs. Explanation of abbreviations and symbols used in the descriptions of families https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429187889/63dd0025-042c-4470-8ca7-4c71d437eeb2/content/table101_111_1_B.tif"/>
112NYMPHAEACEAE (incl. Cabombaceae, excl. Nelumbonaceae)
Genera
5–9 Cabomba, Euryale, Nuphar and Nymphaea (water lily), Victoria.
Species
50–90.
Distribution
Cosmopolitan.
Description of the family
Habit:
Perennial herbs, aquatic, found in fresh water. Rhizomes. Stem immersed.
Leaves:
Alternate, long-petiolate, simple, cordate or peltate, generally floating.
Inflorescence:
Flower solitary, large and showy.
Flower:
3–6 S / 3-n P / 3-n St / 2-n C. Long-pedicellate, large, spiralate, homoio- or heterochlamydeous, actinomorphic, polystemonous, hypogynous or epigynous, bisexual. Sepals often petaloid. Petals often indefinite resulting from the gradual transformation of stamens. Many lamellar stamens sometimes staminodal; anthers with longitudinal dehiscence. Ovary superior or inferior, multilocular, many free or connate carpels; stigma sessile, united and flat or in a disc above the carpels; placentation laminar, many ovules per locule, anatropous, bitegmic.
Fruit:
Fleshy capsule tough or woody. Small seeds often arillate; endosperm poorly developed, perisperm abundant.
Placement in the systems
• Engler:
Ranunculales
• Thorne:
Nymphaeanae-Nymphaeales
• Cronquist:
Magnoliidae-Nymphaeales
• Dahlgren:
Nymphaeiflorae-Nymphaeales
A, Floral diagram of the genus <italic>Nymphaea</italic> https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429187889/63dd0025-042c-4470-8ca7-4c71d437eeb2/content/fig101_112_1_B.tif"/> <target id="page_113" target-type="page">113</target> <italic>Nymphaea alba</italic>: B, habit; C, longitudinal section of the flower; D, detail of the flat stigma; E, cross-section of the ovary with parietal placentation, laminar; F, tip of an indefinite petal. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429187889/63dd0025-042c-4470-8ca7-4c71d437eeb2/content/fig101_113_1_B.tif"/>114ALISMATACEAE
Genera
12 Alisma (water plantain), Echinodorus, Sagittaria (arrowleaf).
Species
75.
Distribution
Cosmopolitan, well represented in the northern hemisphere. Found in aquatic and marshy environments.
Description of the family
Habit:
Aquatic herbs, rooted at the bottom of the bed. Rhizomes. Latiferous schizogenic ducts.
Leaves:
Basal, alternate, sagittate or linear to cordate; petiole well developed, sheathed.
Inflorescence:
Axillary.
Flower:
3 S / 3 P / (3-) 6 (-n) St / (3-) 6-n C. Heterochlamydeous, trimerous, actinomorphic, diplo- or polystemonous, hypogynous, bisexual. Petals caducous. Three to six stamens in a whorl or many stamens arranged in a spiral; anthers bilocular; pollen multiporous. Nectaries on the receptacle, at the base of floral parts or carpels. Ovary superior, carpels free; style terminal or gynobasic; stigma decurrent; placentation basal, ovule generally solitary, anatropous to amphitropous, bitegmic.
Fruit:
Achenes, rarely follicles dehiscent at the base. Seed non-endospermic.
Placement in the systems
• Engler:
Helobiae-Alismatineae
• Thorne:
Alismatanae-Alismatales
• Cronquist:
Alismatidae-Alismatales
• Dahlgren:
Alismatiflorae
