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(Last Modified On 1/21/2017)
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Description
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Plants 350–600 mm high, with smooth the pubescent cataphylls. Corm globose to horizontally elongate, often rhizome-like, dark red, 15–25 mm long, c. 10 mm diam., old corms sometimes persistent and then attached horizontally; tunics membranous, reddish brown, fragmenting irregularly. Leaves 4 to 6, basal longest, blades usually well developed, reaching to about base of spike, narrowly lanceolate, 5–9 mm wide, margins and main veins moderately to heavily thickened and hyaline, sometimes other veins also somewhat thickened, glabrous to pubescent, sometimes with a dense appressed short pubescence; upper 1 or 2 cauline leaves usually entirely sheathing. Stem unbranched, erect. Spike (3–)5- to 8-flowered, erect; bracts green, (20–)25–30 mm long, often somewhat attenuate and dry apically, inner about 2/3 as long as outer. Flowers scarlet red with lower tepals each with a median white stripe, flowers occasionally entirely yellow; perianth tube c. 15 mm long, expanding uniformly from base to apex, curving outward in upper half; tepals unequal, dorsal largest, 18–21 x c. 12 mm, ascending to more or less horizontal, upper laterals c. 20 mm long, lower 3 tepals 16–18 x c. 6 mm, more or less straight and held at 45 degrees to ground. Filaments 5–8 mm long, unilateral and arcuate, included or barely exserted from tube; anthers 7–8 mm long. Ovary 3–4 mm long; style dividing opposite middle to upper third of anthers, branches 3–4 mm long, expanded gradually in upper half. Capsules narrowly obovoid-ellipsoid, (14–)16–18(–22) mm long; seeds more or less oval, broadly winged, c. 7 x 4–5 mm. Flowering time Mainly December to February, but not infrequently in October and November.
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Country
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Angola, Zambia, Congo (DR)
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Distribution and ecology
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extending across southern central Africa from the western Angolan highlands to western Zambia and southern Congo; flowering occurs from the late dry season in September into the early part of the wet season in December and January; evidenrtly restricted to marshy sites, either permanently wet or drying out at the end of the dry season.
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Diagnosis
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somewhat variable in its foliage, Gladiolus benguellensis can always be recognized by its fairly small flowers with subequal tepals, short perianth tube, and unusually short stamens. The filaments, only 5–8 mm long, are usually included in the tube or just barely exserted. The structure of the flowers and bracts of G. benguellensis is similar to that of G. dalenii and G. melleri although they are about half as large as in those species, the bracts being 20–30 mm long and the upper tepals 21–24 mm long. The small flowers and their short stamens combined with normally heavily thickened leaf margins and midribs distinguish the species from its allies.
The leaves of the type of Gladiolus benguellensis are fairly broad, 10–14 mm wide, and quite glabrous and matched in this by the type of Tritonia tigrina and several other collections, including Antunes 29 (type of G. macrophlebius), which is particularly robust. The leaves of the type collection of G. paxii differ substantially in being narrower and less prominently thickened on the margins, and the intercostal areas are covered by a fine dense appressed pubescence. Other collections from the Malange area of western Angola also have lightly pubescent leaves. Plants from there sometimes also have newly emergent leaves with lightly thickened margins and an erect, globose, instead of horizontally elongate, corm. A collection from the drier southern part of Angola, Baum 632, has narrow leaves with especially heavily thickened margins and pubescence only on the upper cataphyll.
White-flowered Gladiolus manikaensis from the Manika Plateau in western central Shaba Province, Zaire, is easily mistaken for G. benguellensis in the vegetative state, both in the peculiar rhizomelike corms with dark brown tunics and leaves with heavily thickened margins and oblique apices. In addition to perianth color, the flowers of the two species differ in size and in the orientation of the lower tepals. In G. manikaensis the upper tepal is c. 25 mm long, compared with 18–21 mm in G. benguellensis, and the lower three tepals curve downward, unlike the nearly straight tepals of G. benguellensis. Both species have short, included filaments, but in G. manikaensis the style divides near the anther apices, and the fairly long style branches exceed the anthers. In G. benguellensis the shorter style branches do not normally reach the anther apices.
Over most of its range G. benguellensis has bright red flowers, but populations with yellow flowers occur locally in southern Angola, where the type of yellow-flowered G. longanus was collected.
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