Mortonia

Shrubs. Branchlets terete, scabrous. Leaves persistent, alternate, crowded; stipules present; petiole essentially absent; blade margins entire; 1-veined. Inflorescences terminal, cymose panicles or racemes. Flowers bisexual, radially symmetric; perianth and androecium perigynous; hypanthium free from ovary; sepals 5, distinct; petals 5, white; nectary intrastaminal, usually lining hypanthium, fleshy; stamens 5, adnate to nectary margin; staminodes 0; pistil 5-carpellate; ovary superior, 5-locular, placentation axile; style 1; stigmas 5; ovules 2 per locule. Fruits nutlike (small, hard-walled, indehiscent), 1-locular, oblong to cylindric, apex beaked. Seeds 1 per fruit, oblong, not winged; aril absent.

Distribution

sw United States, Mexico, Central America.

Discussion

Species 8–10 (4 in the flora).

Mortonia is poorly understood taxonomically.

Selected References

None.

Lower Taxa

Mortonia greggii, Mortonia scabrella, Mortonia sempervirens, Mortonia utahensis

Keys

2	Leaf blades ovate or broadly elliptic to suborbiculate, 5–16 × 4–12 mm, length 1.2–1.4 times width.	> 3
3	Leaves 5–6 × 4–5 mm; fruits 3.5–4.5 mm.	Mortonia scabrella
3	Leaves 7–16 × 5–12 mm; fruits 5–7 mm.	Mortonia utahensis

1	Leaf blades linear-oblanceolate or oblanceolate, 15–25 mm, length 5 times width, glabrous, pliable, margins often thickened, not revolute.	Mortonia greggii
1	Leaf blades ovate, elliptic, oblong-elliptic, suborbiculate, or obovate, 3–16 mm, length 1.2–2.5 times length, usually scabridulous, rarely glabrous, rigid, margins not thickened, revolute.	> 2
2	Leaf blades oblong-elliptic to narrowly obovate, 3–5 × 1.5–2 mm, length 2–2.5 times width.	Mortonia sempervirens
2	Leaf blades ovate or broadly elliptic to suborbiculate, 5–16 × 4–12 mm, length 1.2–1.4 times width.	> 3
3	Leaves 5–6 × 4–5 mm; fruits 3.5–4.5 mm.	Mortonia scabrella
3	Leaves 7–16 × 5–12 mm; fruits 5–7 mm.	Mortonia utahensis