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(Last Modified On 11/16/2016)
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Description:
Deciduous geophytes. Rootstock a depressed-globose corm rooting from below, those of past seasons often not resorbed, producing thin rhizomes from base in some spp., tunics firm-papery, sometimes becoming fibrous with age. Stem smooth, rarely ridged, simple or branched, sometimes repeatedly and strongly flexuose. Leaves several, firm-textured, either plane with prominent main vein, or pleated with prominent vein at each fold, mostly basal and forming a 2-ranked fan, lanceolate to sword-shaped, cauline few and reduced; leaf margins without marginal vein, epidermal cells columnar with thickened walls. Inflorescence a spike, flowers either arranged in 2 ranks or lying on one side of axis, usually many and crowded, axes often strongly flexuose; bracts small, green, becoming dry at tips, firm-textured, inner ± as long as outer and notched apically. Flowers zygomorphic, funnel-shaped to tubular or actinomorphic and pendent, shades of yellow or orange to scarlet, lower tepals sometimes with contrasting markings or green, unscented, with nectar from septal nectaries; perianth tube cylindric or funnel-shaped, widening gradually and flared or tubular above; tepals equal or unequal, then dorsal largest. Stamens unilateral and arched, sometimes lying against dorsal tepal, or symmetrically disposed and central; filaments included to well exserted; anthers parallel, subversatile. Ovary ovoid, enclosed by bracts; style exserted, ascending or arching over stamens or pendent, branches filiform or expanded apically, notched at tips. Capsules depressed-globose, 3-lobed, leathery, often warty above, sometimes reddish to orange inside. Seeds globose or angular and prismatic, several–2 per locule, brown or reddish to black, either shiny and smooth when fresh, coat at least sometimes fleshy and wrinkled on drying, or soft and spongy, the raphal vascular trace excluded. Pollen grains monosulcate-operculate, operculum 2-banded; exine perforate-scabrate. Basic chromosome number x = 11.
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Etymology:
from the Greek krokos, that is, crocus, the source of the culinary herb saffron, and osme, scent, thus ‘smelling of saffron’; the grammatically more correct form Crocosma was often used in the 19th century but Crocosmia is now firmly established. The flowers also produce an orange, saffron-coloured dye.
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General Notes:
Species 8, confined to Africa south of the Sahara and Madagascar (1 sp.), mostly eastern southern Africa, including Lesotho, South Africa, Swaziland and Mozambique; 1 endemic to Namaqualand, Northern Cape.
Crocosmia closely resembles the larger southern and tropical African genus Tritonia, which has some 30 species mostly with orange flowers and short, dry floral bracts. The resemblance is misleading: DNA sequence data from several chloroplast genes shows that Crocosmia is most closely related to Devia, a local endemic with a single species of the Roggeveld Plateau near Sutherland in South Africa; together the two genera are related to the African Freesia, with 16 species. Similarities between Crocosmia and Chasmanthe in flower form and general habit, long thought to indicate close relationship, are likewise misleading. Chasmanthe is related to Tritonia, though according to available molecular data, not its immediate ally. Similarities shared between Crocosmia and Chasmanthe are probably associated with their pollination systems. Flowers of three species are adapted for pollination by sunbirds (Nectarinia), and like all bird-pollinated flowers they have reddish to orange pigmentation, long stamens and an elongate, relatively wide perianth tube. Flowers of other species are adapted for pollination by butterflies or bees.
Popular garden plants, species and a range of hybrids of Crocosmia sometimes referred to as Montbretia) are widely grown. New cultivars are frequently introduced, both for garden display and for the cut flower trade.
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