Mortonia

A. Gray

Smithsonian Contr. Knowl. 3(5): 34, plate 4. 1852.

Etymology: For Samuel George Morton, 1799–1851, North American naturalist
Treatment appears in FNA Volume 12. Treatment on page 128. Mentioned on page 112.

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.

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
... more about "Mortonia"
Jinshuang Ma +  and Geoffrey A. Levin +
A. Gray +
sw United States +, Mexico +  and Central America. +
For Samuel George Morton, 1799–1851, North American naturalist +
Smithsonian Contr. Knowl. +
Mortonia +
Celastraceae +