NYMPHAEACEAE

WATERLILY FAMILY

William J. Stone

Perennial, aquatic; caudex or rhizome generally horizontal, generally large
Leaves alternate, arising directly from caudex; petiole long; blades generally floating, submersed, or slightly emergent
Inflorescence: flowers solitary, axillary; peduncle long
Flowers generally bisexual; sepals 3–many, sometimes petal-like; petals 0–many, sometimes scale- or stamen-like, inserted on receptacle or side of ovary; stamens many, spirally arranged, filaments generally broad; ovary ± compound, superior to inferior, chambers 5–many, ovules many, styles finger-like or 0
Fruit spongy, berry-like
Genera in family: 6 genera, ± 60 species: worldwide.

NUPHAR

COW-LILY, YELLOW POND-LILY

Rhizomes prostrate, branched
Leaf: petioles generally cylindric in X -section; blade generally ovate to round, base deeply notched
Flower: sepals 5–14, spirally arranged, persistent; petals 10–20, scale- or stamen-like, thick and oblong to thin and spoon-shaped; stamens many, generally yellow, attached to receptacle; ovary compound, superior, chambers narrowed above, top expanded into disk-like stigmatic surface, stigmas in lines radiating from center
Seeds ovoid, smooth
Species in genus: ± 25 species: n hemisphere
Etymology: (Arabic name)
Reference: [Beal 1956 J Elisha Mitchell Sci Soc 72:317–346]

Native

N. lutea (L.) Sm. subsp. polysepala (Engelm.) E.O. Beal

Leaf generally floating; blade 1–4 dm, oblong to ovate, lobes at base rounded to acute
Flower 5–7 cm wide; sepals 7–9(12), < 5 cm, outer ovate, green, inner broadly obovate, yellow to red-tinged; petals ± = stamens, petals, stamens yellow, sometimes red-tinged; stigmatic disk 1.5–2 cm wide, entire to deeply scalloped
Seed 3–5 mm
Ecology: Ponds, slow streams
Elevation: < 2500 m.
Bioregional distribution: Northwestern California, n&c Sierra Nevada, n&c Central Western California, Modoc Plateau
Distribution outside California: to Alaska, Rocky Mtns
Synonyms: N. p. Engelm., Nymphaea p. Greene
Horticultural information: Aquatic (fresh): 1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.
Recent taxonomic note: Nuphar polysepala Engelm.