Mc Kelvey's Century Plant

The name Agave lophantha was mentioned by C. J. W. Schiede (Linnaea 4: 582. 1829) without a description. C. S. Kunth (Enum. Pl. 5: 838. 1850) validated the name, but not before A. univittata was proposed. Neither name is typified nor is any authentic material known. H. S. Gentry (1982) incorrectly retained A. lophantha and it is now widely used. A. J. Breitung (1959) was the first to adopt A. univittata, and that name is taken up here.

Plants acaulescent, usually suckering; rosettes densely cespitose, 3–6 × 5–10 dm. Leaves mostly erect, 30–40(–70) × 3–4.5(–5) cm; blade light green to yellowish green, without bud-prints, linear-lanceolate, stiff, adaxially plane to concave toward apex, abaxially convex toward base; margins undulate to crenate, nonfiliferous, not easily detached, conspicuously armed, teeth single or occasionally double, 4–6(–8) mm, 1–2 cm apart; apical spine reddish to grayish, subulate, 1–1.5(–2) cm. Scape 3–4.5(–5) m. Inflorescences spicate, densely flowered on distal 1/2; bracts caducous, acicular, 3–5 cm; peduncle 4 cm or shorter. Flowers 1 on short pedicel, or 2–7 per cluster, erect, 3.5–4(–4.5) cm; perianth greenish white to yellowish green, tube campanulate, 2–4 × 8–10 mm, limb lobes erect to slightly spreading, subequal, 14–20 mm; stamens long-exserted; filaments inserted on rim of perianth tube, spreading, greenish or lavender, 3–4.5 cm; anthers pale yellow, 15–20 mm; ovary 1.8–2.2 cm, neck constricted 5–7 mm. Capsules sessile or short-pedicellate, oblong and 1.8–2.5 cm or globose and 1.5–2 cm, apex beaked. Seeds 5–6 mm. 2n = 60.

Tex.; Mexico.

Flowering spring.

Sandy flats; 0--100m.

Agave heteracantha Zuccarini; A. lophantha Schiede ex Kunth

Agave univittata, the thorn-crested century plant or thorn-crested agave, is a plant species native to coastal areas of southern Texas and northeastern Mexico, at elevations less than 100 m (300 feet). It has been widely named Agave lophantha by botanists including Howard Scott Gentry, but the name A. univittata is older and therefore more in accord with nomenclatural rules of botany.

Agave univittata has thick, fleshy leaves that are stiff and undulate (wavy) along the margins. It has sharp and prominent spines on the edges and tips of the leaves. Flowering stalk is up to 5 m (16 feet) tall, bearing greenish-white to yellow-ish green flowers.

It is cultivated as an ornamental plant, and in the UK the cultivar 'Quadricolor' has won the Royal Horticultural Society's Award of Garden Merit.

Because the species is widespread and the overall population is stable, it is not considered by the IUCN to be threatened.