Origin and Habitat: Agave utahensisSN|581]]SN|581]] ssp. kaibabensis is found on the high Kaibab Plateau around the Grand Canyon in northern and western Arizona.
Altitude range: 700-2500 metres above sea level.
Habitat and ecology: This species grows on alcareous or sandstone outcrops in desert scrub, pinyon-juniper, or adjacent conifer woodlands.

• Agave utahensis subs. kaibabensis (McKelvey) Gentry
• Agave kaibabensis McKelvey
• Agave utahensis var. kaibabensis (McKelvey) Breitung

• Agave utahensis Engelm. in S.Watson
• Agave haynaldii var. utahensis (Engelm.) A.Terracc.
• Agave utahensis subs. utahensis (Engelm.)
• Agave utahensis var. utahensis (Engelm.)
• Agave newberryi Engelm.
• Agave utahensis var. discreta M.E.Jones
• Agave utahensis var. scaphoidea (Greenm. & Roush) M.E.Jones
• Agave scaphoidea Greenm. & Roush

• Agave utahensis var. eborispina (Hester) Breitung
• Agave eborispina Hester

• Agave utahensis subs. kaibabensis (McKelvey) Gentry
• Agave kaibabensis McKelvey
• Agave utahensis var. kaibabensis (McKelvey) Breitung

• Agave utahensis var. nevadensis Engelm. ex Greenm. & Roush
• Agave nevadensis (Engelm. ex Greenm. & Roush) Hester

Description: Agave utahensisSN|581]]SN|581]] ssp. kaibabensis is an uncommon form of the Utah Century plant (Agave utahensisSN|581]]SN|581]]) and is the largest and more robust growing subspecies of this group. It forms attractive solitary rosettes with long, stout, narrow bright green, leaves and grey-white teeth. The plant eventually blooms with very tall flower spikes up to 4.5 or more meters tall. In bloom, the flowering stalks can reach to nearly 6 meters in height.
Stem: Nearly stemless or forming a short trunk with age.
Rosettes: (20-)45-60 cm tall, and 40-60(-100) cm in diameter, usually solitary with numerous leaves.
Leaves: Mostly 30-50 cm long, 3-5.5 cm wide, blade lanceolate to long-acuminate, light to bright green, younger leaves often pruinose-glaucous and firm-fleshed. Marginal teeth (2-)3-5 mm long, 1-4 cm apart, blunt, deltoid, little curved, grayish to white. Apical spine stout, subulate, (2-)3-4 cm long, flat to hollowed above, roundly angled below, grey to white, long decurrent to upper teeth. Cultivated plants often develop longer leaves, up to 55 cm long.
Inflorescence: Narrowly paniculate 3.5-5 m tall, stout, scape 4-6 cm in diameter, part-inflorescences many, slender (1-)7-10 cm long with 4-12 clustered flowers.
Flowers: as in ssp. utahensis but larger, (2.6–)2.9–4.3 cm long. Ovary 1.5–2.9 cm.
Blooming season: Flowering mid spring-early summer.
Chromosome number: 2n = 60.

Bibliography: Major references and further lectures
1) "Agave utahensis ssp. kaibabensis" in: High County Gardens web: https://www.highcountrygardens.com/perennial-plants/agave/agave-utahensis-ssp-kaibabensis
2) Howard Scott Gentry "Agaves of Continental North America" University of Arizona Press, 01 February 2004
3) "Agave utahensis subsp. kaibabensis" in Flora of North America, Vol 26, Page 451 retrieved on 10 October 2017 from http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242102131
4) Urs Eggli, Leonard E. Newton "Etymological Dictionary of Succulent Plant Names" Springer Science & Business Media, 29 June 2013

Cultivation and Propagation: These slow growing plants are quite cold hardy where winters are dry.