Agavaceae

Wavy-leaved soap plant Chlorogalum pomeridianum, copyright Dana L. Brown.

Belongs within: Petrosaviidae.
Contains: Agavoideae.

The Agavaceae are a family of narrow-leaved flowering plants, usually bearing flowers in large panicles. Historically used for a broad range of large and/or arborescent petalous monocotyledons, the family is now more narrowly defined. Leaves are arranged in a spiral rosette and may be succulent or fibrous with margins serrate or toothed. Leaves may also end in a sharp, horny tip or pungent spine. Many species are popular as garden plants.

Phylogenetic analyses indicate a basal position in the family for the Chlorogaloideae, bulbous herbs from North America bearing keeled leaves and white, greenish or blue flowers with superior ovaries (Eggli & Nyffeler 2020).

Characters (from Eggli & Nyffeler 2020): Small to often large perennial rossette plants or (sometimes bulbous) herbs, or shrubs or trees, rosette monocarpic, either unbranched and plant monocarpic, or branched and whole plant polycarpic, terrestrial, very rarely epiphytic; stems none or short (then not rarely caespitose), or arborescent (then mostly branching), in part with secondary thickening growth, partly with spreading or thick and upright rhizomes; leaves spirally arranged in rosette, dorsiventral, lanceolate, linear or subulate, often broadest near the base or the middle and gradually tapering towards the tip, deciduous or more commonly evergreen and then usually thick and succulent, tough and fibrous or thin and weak, tip often a hard pungent spine or a soft (more rarely hard) point or not differentiated, margins entire, hardened in most perennial taxa but soft in herbaceous taxa, or with horny marginal teeth (these often on prominences), or filiferous; inflorescence terminal, mostly large, 0.5–13 m, with few or numerous bracts, determinate and mostly complex much-branched panicles with cymose lateral part-inflorescence consisting of monochasial units; peduncle mostly present, more rarely short to nearly none; peduncular bracts mostly similar to rosette leaves, diminishing in size upwards; floral bracts present; pedicel normally present; flowers bisexual, 3-merous, actinomorphic or slightly zygomorphic, pendent or spreading, or upright, anthesis diurnal and/or nocturnal; tepals 3 + 3, mostly whitish to yellow or greenish, rarely reddish, pinkish or brownish, or lavender or blue, tepals spreading or connivent to form a tube-like structure, or fused for part of their length and forming a tubular to campanulate tube, sometimes abruptly widened or urceolate in the upper part; stamens 3 + 3, inserted at or somewhat above the base of the free tepals or within the perianth tube; filaments mostly long and slender-filiform, rarely short, sometimes widened basally or apically, mostly glabrous, sometimes puberulent; anthers dorsifixed, 2-thecous, small to large, sagittate to hastate or oblong to linear, long or short, dehiscing introrsely with longitudinal slits; pollen primarily sulcate, rarely bisulcate, mainly released in monads, rarely also in tetrads; ovary inferior or superior, 3-locular, each locule with 2 to several to mostly many ovules; nectary septal; style rather long and simple or apically with 3 free and short branches; stigma mostly single and either capitate or 3-lobed or on 3 style branches, surface dry or wet; fruit mostly loculicidal capsules, rarely septicidal capsules or berry-like, with several to many seeds; seeds various but mostly flat and plate-like, crescent-shaped or semicircular, but sometimes less compressed, or globose, ovoid or pear-shaped, black (due to phytomelans).

<==Agavaceae [Agavales, Chlorogalaceae, Dracaeneae, Funkiaceae, Hesperocallidaceae, Hostaceae, Yuccaceae] EN20
    |  i. s.: Asteliaephyllum italicum Squinabol 1892 CBH93
    |--+--Agavoideae EN20
    |  |--Hosta [Hosteae] EN20
    |  |    `--H. ventricosa V72
    |  `--+--Hesperoyucca (Engelmann) Trelease 1893 (see below for synonymy) EN20
    |     |    |--*H. whipplei (Torrey) Trelease 1893 (see below for synonymy) EN20
    |     |    `--H. newberryi (McKelvey) Clary 2001 (see below for synonymy) EN20
    |     `--Hesperaloe Engelmann in Watson 1871 EN20
    |          |--H. parviflora (Torrey) Coulter 1894 (see below for synonymy) EN20
    |          |    |--H. p. ssp. parviflora EN20
    |          |    `--H. p. ssp. bechtoldii Hochstätter 2009 (see below for synonymy) EN20
    |          |--H. campanulata Starr 1998 EN20
    |          |--H. chiangii (Starr) Turner 2002 [=H. funifera ssp. chiangii Starr 1998] EN20
    |          |--H. engelmannii Krauskopf 1878 [=H. parviflora var. engelmannii (Krauskopf) Trelease 1902] EN20
    |          |--H. funifera (Koch) Trelease 1902 (see below for synonymy) EN20
    |          |--H. malacophylla Hochstätter & Martínez-Ávalos 2010 EN20
    |          |--H. nocturna Gentry 1967 EN20
    |          `--H. tenuifolia Starr 1998 EN20
    `--Chlorogaloideae EN20
         |--Hesperocallis undulata EN20, H93
         |--Hastingsia EN20
         |    |--H. alba [=Schoenolirion album] H93
         |    `--H. serpentinicola H93
         |--Camassia EN20
         |    |--C. cusickii V09
         |    |--C. quamash H93
         |    |    |--C. q. ssp. quamash [incl. C. quamash ssp. linearis, C. leichtlinii ssp. suksdorfii] H93
         |    |    `--C. q. ssp. breviflora H93
         |    `--C. scilloides V72
         `--Chlorogalum EN20
              |--C. angustifolium H93
              |--C. grandiflorum H93
              |--C. parviflorum H93
              |--C. pomeridianum H93
              |    |--C. p. var. pomeridianum H93
              |    |--C. p. var. divaricatum H93
              |    `--C. p. var. minus H93
              `--C. purpureum H93
                   |--C. p. var. purpureum H93
                   `--C. p. var. reductum H93

Hesperaloe funifera (Koch) Trelease 1902 [=Yucca funifera Koch 1862, Agave funifera (Koch) Lemaire 1864; incl. Hesperaloe davyi Baker 1898] EN20

Hesperaloe parviflora (Torrey) Coulter 1894 [=Yucca parviflora Torrey 1859; incl. Aloe yuccifolia Gray 1867 (nom. illeg.), *Hesperaloe yuccifolia (Gray) Engelmann 1871 (nom. illeg.)] EN20

Hesperaloe parviflora ssp. bechtoldii Hochstätter 2009 [=H. bechtoldii (Hochstätter) Hochstätter 2016 (nom. inv.); incl. H. yuccoides (nom. inv.)] EN20

Hesperoyucca (Engelmann) Trelease 1893 [=Yucca (Hesperoyucca Engelmann 1871), Y. subg. Hesperoyucca (Engelmann) Baker 1876] EN20

Hesperoyucca newberryi (McKelvey) Clary 2001 [=Yucca newberryi McKelvey 1947, Y. whipplei ssp. newberryi (McKelvey) Hochstätter 2000; incl. Y. newberryi ssp. mckelveyana Hochstätter 2015] EN20

*Hesperoyucca whipplei (Torrey) Trelease 1893 [=Yucca whipplei Torrey 1859; incl. Y. californica Groenland 1858, Y. whipplei var. caespitosa Jones 1929, Y. whipplei ssp. caespitosa (Jones) Haines 1942, Y. engelmannii Masters 1880, Y. whipplei ssp. eremica Epling & Haines 1957, Y. graminifolia Wood 1868 non Zuccarini 1837, Hesperoyucca whipplei var. graminifolia Trelease 1893, Y. whipplei f. graminifolia (Trelease) Voss 1895, Y. whipplei ssp. intermedia Haines 1941 non Y. stricta var. ntermedia Carrière 1859, Y. whipplei var. intermedia (Haines) Webber 1953, Y. nitida Wright ex Watson 1906, Y. ortgiesiana Roezl 1880, Y. whipplei var. parishii Jones 1929, Y. whipplei ssp. parishii (Jones) Haines 1941, Y. peninsularis McKelvey 1947, Hesperoyucca peninsularis (McKelvey) Clary 2001, Y. whipplei ssp. percursa Haines 1941, Y. whipplei var. percursa (Haines) Webber 1953, Y. whipplei ssp. rigata Afferni & Drovandi ex Afferni 2004, Y. whipplei ssp. typica Haines 1941 (nom. inv.), Y. whipplei var. violacea André 1884] EN20

*Type species of generic name indicated

REFERENCES

[CBH93] Collinson, M. E., M. C. Boulter & P. L. Holmes. 1993. Magnoliophyta (‘Angiospermae’). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 809–841. Chapman & Hall: London.

[EN20] Eggli, U., & R. Nyffeler (eds) 2020. Illustrated Handbook of Succulent Plants: Monocotyledons 2^nd ed. Springer.

[H93] Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).

[V09] Verdcourt, B. (ed.) 2009. Additions to the wild fauna and flora of the Royal Botanic Gardens, Kew. XXVI. Miscellaneous records. Kew Bulletin 64 (1): 183–194.

[V72] Voss, E. G. 1972. Michigan Flora. Part I. Gymnosperms and Monocots. Cranbrook Institute of Science and University of Michigan Herbarium.

Last updated: 8 June 2022.