Gladiolus sp.



Gladiolus sp.

L. 1753

pronounced: glad-ee-OH-luss species

(Iridaceae — the iris family)


common names: gladiolus, sword lily

Gladiolus is Latin for ‘little sword’, referring to the shape of the leaf. The genus contains about 180 species, most of which are native to sub-Saharan Africa, principally South Africa; there are about 10 species native to Eurasia. The flowers of unmodified wild species vary from very small to about 4 cm across, with inflorescences bearing anything from one to several flowers. The spectacular giant flower spikes we see in our gardens and in florists’ shops are the products of centuries of hybridization and selection.

These are perennial herbs, growing from rounded, symmetrical corms that are enveloped in several layers of brownish, fibrous tunics.

The stems are generally unbranched, producing up to about 9 narrow. sword-shaped, longitudinally grooved leaves, enclosed in a sheath. The lowest leaf is shortened to a cataphyll. The leaf blades can be plane or cruciform in cross-section.

The fragrant flower spikes are large and one-sided, with secund, bisexual flowers, each subtended by 2 leathery green bracts. The flowers are variously coloured: most colours are available; many have markings on the petals, and some have ruffled edges. The sepals and the petals are almost identical in appearance, and are termed tepals. They are united at their base into a tube-shaped structure. The dorsal tepal is the largest, arching over the 3 stamens, while the outer 3 tepals are narrower. The perianth is infundibuliform, with the stamens attached to its base. The style has 3 filiform, spoon-shaped branches, each expanding towards the apex. The ovary is 3-locular with oblong or globose capsules containing many winged brown longitudinally dehiscent seeds.

The South African species were originally pollinated by long-tongued bees of the Anthophoridae family, but changes in flower shape now allow pollination by sunbirds, moths, long-tongued flies and several other pollinators. In temperate zones, many of the hybrid large-flowering sorts of gladioli can be pollinated by wasps (not very efficiently) or by the European Hawk-moth Macroglossum stellatarum.

Roasted Gladiolus corms were a food source for southern African tribes, and are said to taste like chestnuts.

Gladiolus species and cultivars need a sunny position with moist, well-drained soil; the corms are usually planted at 4 times their own depth. The plants should be watered well while in bloom, and then allowed to dry out. The plants produce cormlets, which can be planted out for propagation purposes. Gladioli make excellent cut flowers; but, due to the height of the flower spikes, they will often fall over in the garden, especially in windy weather.


Photographs taken in Picnic Bay 2011
Page last updated 4th January 2019