Accepted Scientific Name: Agave univittata Haw.
Philos. Mag. Ann. Chem. 10: 415 (1831)
Origin and Habitat: USA (Texas), Mexico (Coahuila, Nuevo Leon, Tamaulipas, San Luis Potosi, Veracruz, Puebla)
Altitude range: 0–1500 metres above sea level.
Habitat: Frequent on limestone in sandy flat.
Synonyms:
See all synonyms of Agave univittata
Common Names include:
ENGLISH: Agave, McKelvey's Agave, Center Stripe Agave, Thorn-crested Agave
ARABIC ( لعربية ): أغاف أحادي الخطوط
CHINESE (中文): 單帶龍舌蘭
DUTCH (Nederlands): Tampicohennep, Pitavezel
SICILIAN (Sicilianu): Centuspati
SPANISH (Español): Maguey mezortillo
Description: Agave univittataSN|25296]]SN|25296]] (syn: Agave lophanthaSN|25300]]SN|25300]]) is an stemless, usually suckering agave that forms dense clumps to 60 cm tall by 1.5 m wide composed of very regular leaf rosettes of a light green to yellow-green, with or without pale mid-stripe. Leaves wide at the base, long tapering grey-green, slightly hollow on the upper side with or without pale mid-stripe, marginal spines stout, curved downwards, terminal spine very sharp, 25 mm long. It is extremely variable and has many varieties and forms.
Stem: Very short sometimes visible on old plants.
Rosettes. Small, loose, about 30-leaved, 30-60 cm tall, 50–100 cm wide, solitary or usually forming offsets.
Leaves: Numerous, linear to lanceolate, stiff, mostly erect, without noticeable bud-prints, rather thin, pliant, somewhat thickened towards the base and rounded below, plane to concave above, back convex and with darker lines, generally 30-70 cm long, 3-5 cm wide, light green to yellow-green, with or without pale mid-stripe. Margins horny, undulate to crenate, without threads, not easily detached, conspicuously armed. Marginal teeth single or occasionally double, triangular, straight or mildly curved, slender, mostly 4-8 mm, 1-2 cm apart, on broad low prominences. Terminal spine subulate, flattened above at the base, small, 1- 2 cm, ferruginous to grey.
Inflorescence: Slender 3–4.5(–5) m tall, `spicate', flowers in the upper half of the scape spike somewhat sinuous above, 190-200 cm long, dense towards the tip. Bracts caducous, acicular, 3–5 cm long. Part inflorescences with 1- 2 flowers or also with 3-7 on short stalks. Peduncle 4 cm or shorter.
Flowers. Flowers pale greenish-yellow 35-47(-55) mm long on short pedicels (5-10 mm long). Ovary fusiform, 18-22 mm, neck short or long (5-7 mm) and constricted. Tepals light grey-glaucous-green to yellowish-green, tube short, campanulate, 2-4 mm long, 8–10 mm wide, lobes subequal, erect to slightly spreading, 14-20 mm long. Stamens exserted. Filaments inserted on rim of perianth tube, spreading, greenish or lavender, 3–4.5 cm long. Anthers yellow, 15–20 mm long.
Phenology: March-may (spring).
Fruits (capsules: Sessile or short-pedicellate, oblong and 1.8–2.5 cm long, or globose and 1.5–2 cm on diameter, apex beaked.
Seeds: 5–6 mm long.
Chromosome number: 2n = 60.
Remarks: The name Agave lophanthaSN|25300]]SN|25300]] 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 Agave univittataSN|25296]]SN|25296]] 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.
Subspecies, varieties, forms and cultivars of plants belonging to the Agave univittata group
- Agave lophantha var. pallida A.Berger: rosette 25—30-leaved, 50 to 55 cm in diameter. Leaves to 50 cm long, and 25 mm wide, pale green, darker towards the margins, margins with narrow, detaching horny lines, spines hooked, 2.5-5 cm apart, 8-10 mm long.
- Agave lophantha var. poselgeri (Salm-Dyck) A.Berger: has a free suckering habit and occurs in a variety of forms. Leaves only 20-26 cm long, 16—18 mm wide, sinuous, with a long, fine terminal spine, spines small, distant, absent in the upper part. Distribution: Mexico: Plateau near El Paso; Texas.
- Agave univittata Haw.: stemless, 30-60 cm tall, 50–100 cm wide, usually forming offsets. Leaves light green, with or without pale mid-stripe, marginal spines stout, curved downwards, terminal spine 25 mm long. It is extremely variable. Distribution: USA (Texas), Mexico (Coahuila, Nuevo Leon, Tamaulipas, San Luis Potosi, Veracruz, Puebla)
- Agave univittata var. angustifolia (A.Berger) H.Jacobsen: (Variegated form) Leaves not numerous, 75 cm long, 2.5 c. wide, terminal spine slender, leaf dark green on the upper side, more grey-green on the reverse, with numerous darker cross-lines, marginal spines small, 2—7 cm distant.
- Agave univittata var. brevifolia (Jacobi) H.Jacobsen: Leaves 32—33 cm long, 5 cm wide at the base, 3.5 cm wide above the centre, gradually tapering towards the tip, ending in a blunt tip, leaf colour without green longitudinal lines.
- Agave univittata var. coerulescens (Salm-Dyck) H.Jacobsen: Similar to the species; Leaves somewhat shorter and more numerous, rough, light blue-grey, without pale band, spines rather stout, directed downward.
- Agave univittata var. gracilior (Jacobi) H.Jacobsen: Rosette very regular. Leaves more numerous, slender, more narrow, leaf margins more light grey, spines much closer and with browned tip.
- Agave univittata var. latifolia (A.Berger) Breitung: has larger, very dense-leaved rosettes 130—150 cm in diameter, 75—100 cm high, forming offsets. Leaves sword-shaped, 73-76 cm long, below 5.5 cm, at the centre 6 cm wide.
- Agave univittata var. lophantha (Schiede ex Kunth) Maire & Weiller: Same as Agave univittata, and the two plants are not readily distinguishable.
- Agave univittata var. lophantha f. quadricolor: Solitary or slowly clumping succulent rosette, up to 40 cm tall, 60 cm in diameter. Leaves variegated with four distinct colours.
- Agave univittata var. subcanescens (Jacobi) H.Jacobsen: Leaf margins and marginal spines almost white, leaf colour grey-green.
- Agave univittata var. tamaulipasana (A.Berger): Leaves 30-40 cm long, 25—35 mm wide, terminal spine conical, margins with a fine horny edge, marginal spines 15-20 mm apart, 3—7 mm. Distribution: Mexico, Taumalipas.
Notes: This species has often been misinterpreted. It is distinguished from the closely related Agave lechuguillaSN|25296]]SN|23013]] by its flatter leaves with sinuous to undulate firm borders, tubercles usually with at least one double set of teeth (frequently more), and with teeth that are more slender and closely set. Moreover Agave univittataSN|23013]]SN|25296]]'s leaves are wider in the middle. Some A. lechuguilla have a stripe in the middle, though faint, but A. univittata always has the brighter stripe on the average and sometimes faded. A. univittata doesn't have the dark broken streaks on the outside of the leaf.
Bibliography: Major references and further lectures
1) Hermann Jacobsen “Abromeitiella to Euphorbia” Blandford Press, 1960
2) Urs Eggli “Illustrated Handbook of Succulent Plants: Monocotyledons” Springer Science & Business Media, 06 December 2012
3) Wendy C. Hodgson “5. Agave univittata Haworth, Philos. Mag. Ann. Chem. 10: 415. 1831. Thorn-crested agave” in Flora of North America, FNA Vol. 26 Page 444, 449 retrieved on 17 June 2016 from <http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242101320>
4) Howard Scott Gentry “Agaves of Continental North America” University of Arizona Press, 01 February 2004
Cultivation and Propagation: It is a relatively easy-to-grow species. If grown in a pot, it is a wonderful looking species.
Exposure: Suited for light shade to full sun, but better with some shade in summer. Plants cultivated outdoors are more drought tolerant and can take some heat and full sun.
Soil: It does great in containers or in the ground. It needs a very well-drained soil.
Water requirements: It grows fairly fast in summer if provided with copious water, but allow to dry thoroughly before watering again (the more water and fertilizer this plant gets, the faster it will grow). During the winter months, one should only water enough to keep the leaves from shrivelling.
Hardiness: It is frost tolerant to -5° C, but it is best to avoid freezing temperatures.
Maintenance: Remove suckers to show off the beauty and form of the individual rosette.
Warning: Though this is a pretty striking Agave, it suckers into one of the most intensely spiny, dangerous cluster of plants you can imagine and it is nearly impossible to remove suckers and the spines can go through your boots.
Propagation: By suckers, which often are found growing around the base of the plant, Remove the basal suckers (if available) in spring or summer and let the cuttings dry for a few days before inserting into compost.