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(Last Modified On 1/13/2017)
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Description:
Plants 240–350 mm high with dry often brittle cataphylls. Corm 10–20 mm diam.; tunics of fine to coarse yellow brown to gray fibers, usually accumulating in a dense mass, often extending upward and with the dry cataphylls forming a thick collar. Leaves (3–)4 to 5, lower 2 to 4 more or less basal, linear (rarely lanceolate), reaching to at least base of spike or sometimes lower shortly exceeding it, 1.5–3(–5–7) mm wide, tmargins not thickened, decreasing in size above, uppermost usually cauline. Stem erect, unbranched, c. 2 mm diam. at spike base. Spike 4- to 10-flowered, inflexed at the base, straight, sheathed by the bracts; bracts green or becoming dry and brown apically, firm and erect, clasping stem, usually imbricate, about 2 internodes long, occasionally (1–)1.5 internodes long, 18–25 mm long, the inner about 2/3 as long as outer. Flowers either light to dark purple fading to cream in the throat and tube, lower tepals each with a yellow median streak in upper third, or uniformly dark purple; perianth tube 10–12 mm long, curving outward and widening above; tepals unequal, dorsal c. 18 x 10–12 mm, arched over stamens, lower 3 united with upper laterals for c. 4.5 mm and to each other for c. 2 mm, narrowed below into claws, horizontal or limbs flexed downward distally, in profile usually shortly exceeding upper. Filaments 10–12 mm long, exserted 5–6 mm from tube; anthers c. 6 mm long, usually purple, pollen yellow. Ovary ellipsoid, 4–5 mm long; style arched over stamens, dividing opposite lower third of anthers, branches 1–1.5 mm long. Capsules narrowly elliptic, 10–12 mm long, comparatively hard and woody; seeds angular, wingless but with a prominent membranous ridge on one end, c. 1.2 x 2.5 mm. Chromosome number 2n = 22. Flowering time: January to mid March.
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Country:
Zambia, Congo (DR)
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Distribution and ecology:
centered in southern Congo, where it is most common in rocky grassland on soils that are enriched with heavy metals; usually in open and sunny situations (this contrasts with the closely related G. gregarius, which favors light woodland, frequently on deeper soils). There are scattered records of G. microspicatus from elsewhere in Katanga and in Burundi and northeastern Zambia and adjacent Tanzania, where plants grow in well-drained, often dry grassland or rock outcrops, sometimes in poor sandy soils.
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Diagnosis:
resembling a diminutive G. gregarius and immediately related to this species, the two sharing a similar moderate-sized purple and cream flower with a pale throat, stiff, erect, imbricate bracts that clasp the stem, and short ellipsoid capsules that remain enclosed in the bracts until the latter decay. The major differences are the presence of a collar of fibers around the stem base, narrow leaves, usually 1–2 mm wide (sometimes up to 4 mm), and wingless seeds. First described as variety angustifolius of Gladiolus klattianus (a synonym of G. gregarius), the plant was redescribed at species rank as G. microspicatus (Còrdova, 1990), without reference to the earlier varietal name, although including among the exsiccatae cited the type of variety angustifolius. As circumscribed here, G. microspicatus includes not only plants from heavy-metal-enriched soils of southern Katanga but some from elsewhere in Congo as well as from adjacent northern Zambia and Burundi. Away from heavy-metal-enriched soils, plants are recorded as growing on sandy or stony sites in moist grassland or steppe. No capsulate specimens are known from these sites and seeds cannot be compared with those from such heavy-metal-enriched soils. However, the corms from non-heavy-metal-enriched sites lack the thick layer of fibers that form a neck around the stem base otherwise characteristic of G. microspicatus.
Until seeds of Gladiolus microspicatus from soils that do not have high concentrations of heavy metal have been examined, the possibility that these populations are independently derived from G. gregarius remains a tenable hypothesis. There seems no doubt that G. microspicatus is not simply an ecotypic variant of G. gregarius. Greenhouse-grown plants from Kasompi West in Katanga maintained their low stature, narrow leaves, and short bracts when cultivated in Belgium. Plants from Chabara, also in Katanga included in G. microspicatus have unusually broad leaves 5–7 mm wide but not reaching the base of the spike. In leaf width they seem to approach G. gregarius, but leaf height and other characteristics accord closely with G. microspicatus. It must be noted that the species is regarded as a variety of G. gregarius in accounts of the genus for Flore d'Afrique Central.
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