Yellow may not be the first color that comes in mind thinking of Gladiolus, but there are some very striking species in this category. Quite often, there is a secondary yellow form of mainly orange or purple Gladiolus species.
Gladiolus alatus L. is a winter rainfall species found on flats, slopes, and plateaus, mainly in sand. The flowers are orange, marked yellow and have a light and pleasant scent. Height is 8-25 cm high. Photo 1 was taken near Paarl September 2003 by Bob Rutemoeller. The next two pictures were taken by Bob Rutemoeller and Mary Sue Ittner near Bainskloof September 2006.
Photos below are a white form of this species. The first photo was taken by Alan Horstmann. The next two photos from Mary Sue Ittner and Bob Rutemoeller were taken near Villiersdorp. The last photo by Bob Rutemoeller shows a white form for sale in a nursery in Caledon.
The photos below are of plants in cultivation. Photo 1 by Mary Sue Ittner shows flowers on a plant grown from seed blooming March 2005. Photo 3 from Bob Werra. Photos 3-6 were taken by Nhu Nguyen. Photo 5 show seeds on a 1 cm square grid.
Gladiolus antholyzoides Baker is distributed across the central and eastern high veld of South Africa. Flowers are yellow, sometimes streaked with red or orange and with an orange ring around the throat. This species was once included in Antholyza as Antholyza laxiflora and Antholyza schlechteri, presumably because of its long perianth tube. It has also had other Gladiolus species names.
Gladiolus aurantiacus Klatt is found in the summer rainfall area often growing in high grassland and is centered in KwaZulu-Natal extending into Mpumalanga and Swaziland. Growing from 45 to 75 cm high, it has stem leaves with short blades and foliage leaves with longer blades that are produced on separate shoots near the end of flowering. The unscented flowers are yellow, dotted or streaked with red or orange which gives them the appearance of being orange borne on a 10 to 16 flowered erect spike. Flowers have an elongate flower tube, slender in the lower half. The dorsal tepal is slightly ascending to horizontal and the lower tepals with yellow blotches in the lower half curve sharply downward. Flowers are adapted for pollination by sunbirds. Flowering is unusual as it occurs early, mostly in September and October, before the main rainy season has started. Photo from Rachel Saunders.
Gladiolus aureus Baker is endangered. It is found in the wild today in only a single location, a peaty seep on a rocky sandstone slope in the Southwest Cape. There are reportedly as few as ten plants remaining at this location. It has bright yellow flowers. The first photo was taken by Rachel Saunders August 2012 at its only known locality. There were five flowering plants surrounded by alien vegetation, houses and destruction. Photos 2-4 were taken by Bob Werra and the last photo by Michael Mace.
Additional information and photos from Ernie DeMarie: I grew three plants from seed that was refrigerated for well over a decade that came from the annual seed distribution of the Botanical Society of South Africa, which unfortunately they no longer do for international members. This species is not self compatible so when all three plants bloomed I was able to cross them and set a good amount of seeds. I distributed seeds or young corms to growers in California, South Africa, Australia, and Argentina in the hopes that this species could be maintained in cultivation as it is gravely endangered at its one locality on the Cape Peninsula.
Gladious aureus is not especially difficult to grow under my conditions but corms can exhaust themselves if they set a lot of seed. It will usually flower the third year from seed. It appears to reproduce mainly by seed; thus far I have not seen evidence of abundant cormlet production as happens with most other gladiolus species. It blooms in February for me. Being a small plant it can be managed under lights more easily than many other gladioli species.
Gladiolus bilineatus G.J.Lewis grows in clay and loamy sand in the fynbos in the Langeberg Center (Southern Cape.) Growing from 20 to 40 cm and flowering March-April, this species has short sword shaped leaves and cream to pink flowers with reddish lines near the base of the lower tepals in a one to three flowered spike. Photos taken March 2016 near Swellendam by Rachel Saunders.
Gladiolus buckerveldii (L.Bolus) Goldblatt is a species restricted to a few sites along permanent rivers in the northern Cederberg of the western Cape. Plants grow out of nearly vertical moss covered cliffs. Growing from 80 to 125 cm, it has a horizontal spike of 12 to 20 ivory to greenish cream flowers, each with a spade or heart shaped dark red mark in the center of the lower tepals. It flowers in summer. In the past it was included in Antholyza as Antholyza buckerveldii because of its elongate floral tube (wide and cylindric above and slender below) and then was moved to Petamenes. In 1971 it was included in Gladiolus. Photos taken January 2014 by Rachel Saunders. It was growing on a cliff next to a waterfall.
Gladiolus carinatus Aiton is found on sandstone slopes or deep coastal sands in many areas of the Cape. It flowers late winter to spring and can be blue to violet or yellow, rarely pink, often with yellow markings on the lower tepals. The first two photos were taken by Mary Sue Ittner; the first photo was taken September 2001 in the Southwest Cape and the second shows the flower of a plant grown from seed and flowering March 2004. The next two were taken by Bob Werra. The last photo from Cameron McMaster shows a yellow form grown from seed by Rhoda McMaster.
The first five photos were taken in the Western Cape in Hopefield, Elands Bay, and near Napier by Cameron McMaster. The last photo is from Rod Saunders.
The photos from Alan Horstmann show different forms.
Gladiolus citrinus Klatt see Gladiolus trichonemifolius
Gladiolus comptonii G.J.Lewis is a rare plant that grows on rocky sandstone slopes in the northwest Cape in a localized area on Heerenlogement Mountain at the northwestern end of the Olifants River Mountains. Plants grow 45 to 60 cm high. The leaves are linear and the few bright yellow short tubed flowers have brown streaks on the lower tepals. This species flowers mid to late July (winter). Photo taken by Rachel Saunders.
Gladiolus dalenii Van Geel is a widespread and common species found not only in Southern Africa, but also in other parts of tropical Africa. It has been known by a number of names over the years; there have been 27 synonyms for the tropical Africa and Madagascar forms and 14 more for the southern African forms. The main synonyms for the southern Africa collections have been Gladiolus natalensis and Gladiolus psittacinus. This species blooms at different times of the year depending on the location, but there are probably flowers every month of the year somewhere in its native habitats. Flowers are either red to orange with yellow markings on the lower half of the three lower tepals or yellow to greenish with red to brown streaks on the upper tepals. Although it favors moist habitats and is often found in grassland, it can also be found in dry habitats with only a short wet season. The ones I grew in Northern California lived for a number of years in the garden, dormant during our wet winters, appearing late spring and surviving through the dry summer and blooming in the fall. The flowering stalks were very tall with a number of flowers. Photos 1-2 of those plants were taken by Mary Sue Ittner. Photo 3 by Cameron McMaster shows plants in cultivation. Photos 4-5 by Mary Hunter and Mary Sue Ittner show the first bloom from seed of a yellow form of ssp. dalenii, once known as Gladiolus primulinus blooming in late summer in Northern California. The last photo by David Pilling shows seed.
The first photo below from Cameron McMaster shows flowering plants in habitat in the Eastern Cape. The second is another habitat shot taken near Balloch in the Eastern Cape, January 2010 by Bob Rutemoeller. Photo Nr. 3 from Rachel Saunders shows an unusual color form and was taken in northern KwaZulu-Natal in January 2015. The last photo shows the beautiful detail on likely the same color form, as the seeds were obtained from Silverhill, flowering the second year from seed for Martin Bohnet.
Gladiolus delpierrei Goldblatt grows on marshy sandstone slopes at 1200 m in the Cederberg Mountains. Growing from 40-45 cm high and blooming December to January, it has yellowish cream flowers with yellow and red marking on the lower tepals. Photo taken January 2014 by Rachel Saunders.
Gladiolus karooicus Goldblatt & J.C.Manning was named in 2009. It is found from the Little Karoo to the Komsberg section of the Roggeveld Escarpment. Photos taken September 2011 by Cameron McMaster near Matjiesfontein.
Gladiolus liliaceus Houtt. grows on clay slopes over a wide area of South Africa (from the Cedarberg Mountains to Port Elizabeth) and blooms winter to spring. Growing from 30 to 80 cm high, the 1 to 4, sometimes 6, flowers are an inclined spike. The large flowers are brown, dull pinkish red, tan, purplish or cream to greenish yellow and turn bluish to mauve in the evenings when they become intensely clove scented. Depending on the location and the elevation with the lower elevations blooming earlier, this species blooms from late August to December.
The ones grown by Mary Sue Ittner have not been very fragrant and the color change is subtle. Photo 1 was taken by Mary Sue Ittner. Photos 2-3 from Bob Rutemoeller attempt to show the change in color. Photo 2 was taken during the day and photo 3 in the early evening. Andrew Harvie's photos (4-5) show the orangey red color of the day and the more purple color of the night. To ensure correct color balance both photos were taken with a flash and same exposure. He notes that he wishes he could also share the fragrance.
The forms pictured below in the first four photos were all found at Drayton and were blooming August-September 2003. Photos by Bob Rutemoeller including a single yellow one. The fifth photo is of a red flowered one photographed by Cameron McMaster near Bredasdorp in the Overberg. The last photo from the book Plants of the Klein Karoo courtesy of Jan and Anne Lise Schutte-Vlok.
Gladiolus longicollis Baker is a species found in a wide area of southern Africa, including the southern Cape, the eastern Cape, the Free State and the Northern Province. It has pale yellow to white long tubed flowers that are either uniformly colored or mottled with brown. Flowers are night blooming and sweetly scented of carnation and cloves. There are two subspecies:
Gladiolus longicollis ssp. longicollis has a shorter perianth tube and transparent upper tepals and flowers October to November. It is found from Oudtshoorn in the Western Cape through the Eastern Cape and Free State and into Lesotho and Gauteng where it usually grows on moist, south facing slopes in low grassy fynbos or rocky grassland.
Gladiolus longicollis ssp. platypetalus (Baker) Goldblatt & J.C.Manning has a longer perianth tube and broader petals with the outer whorl tepals longer than the inner whorl and grows in rocky grasslands from central KwaZulu-Natal to Mpumalanga and Limpopo. Its flowering season extends into January and possibly February.
The first three photos from Cameron McMaster and the next two from Mary Sue Ittner. Photos three thru five were taken at Naude's Nek.
The first photo from the book Plants of the Klein Karoo courtesy of Jan and Anne Lise Schutte-Vlok. They describe it as growing up to 60 cm tall with narrow cylindrical leaves and flowers with red brown spots and lines. The anthers are not much exposed, a characteristic that helps distinguish it from a similar looking Gladiolus tristis. The second photo is from Arnold Trachtenberg.
Gladiolus maculatus Sweet extends across the southern coast and immediate interior of the winter rainfall area to the Eastern Cape where it is often found growing in heavy soils in renosterveld. Flowers are dull yellow to lilac and speckled with brown or purplish spots. They are long-tubed and fragrant during the day and the evening. The first three pictures were taken by Cameron McMaster near Napier and Bredasdorp in the Overberg.
The first two pictures below are of garden flowers taken by Mary Sue Ittner December 2007 and January 2009. The next two were taken by Alan Horstmann and the last by Dirk Wallace.
Gladiolus orchidiflorus Andrews is found on clay and sandstone soils from Namibia to Cape Flats and also to Free State and flowers in the spring. It has linear to sword-shaped leaves that are thickened in the midline. Flowers are in a 5 to 12 flowered spike, windowed in profile, greenish to purple with dark purple markings on the lower tepals, and are very fragrant. Photos 1-2 are habitat shots taken in Namaqualand by Bob Rutemoeller and Mary Sue Ittner September 2006. Photos 3-4 were taken near Carolusberg, Namaqualand by Cameron McMaster September 2011.
The photos below were taken by Alan Horstmann.
Gladiolus pardalinus Goldblatt & J.C.Manning is restricted to the bushveld of Northern Province and Mpumalanga, South Africa where it grows in dolerite in rocky ground. Growing from 35 to 55 cm high, it has usually three leaves that sheath and envelope the stem and 10 to 15 flowers in a spike. Flowers are pale yellow speckled with red brown markings on all except the dorsal tepal. All of the tepals are clawed at the base. This species flowers in early spring, mid October and November. Photo from Rachel Saunders.
Gladiolus pritzelii Diels is found on rocky sandstone slopes in the northwest Cape. It has bell-like yellow fowers with red to brown transverse markings on the lower tepals. The first photo was taken by Cameron McMaster on Ouberg Road in the Roggeveld, the second by Rod Saunders from Silverhill Seeds. The flowers have a mild scent of green apples.
The photos below are of plants in cultivation. Photo 1 was from Alan Horstmann and photos 2-5 were taken by Nhu Nguyen.
Gladiolus pubigerus G.J.Lewis syn. Gladiolus pugioniformis has a strange distribution pattern. It is found in the Eastern Cape and in some areas of Natal, and then in the mountains of Mpumalanga. It has pale lemon yellow flowers tinged with green and flowers in spring. The plants in Mpumalanga are a bit different to those in the Eastern Cape. It flowers well after a fire and not as well in between. The first two photos were taken by Cameron McMaster. The last photo was taken by Rachel Saunders September 2014 in habitat in Mpumalanga near Lydenburg, at an altitude of about 1800 m. It was flowering in a fire break around a pine plantation which was burned sometime in the winter. The area had a small amount of rain in August, and this was obviously enough to stimulate a few plants to flower.
Gladiolus scullyi Baker is found on silty clay and granite slopes in the northern winter rainfall areas (Namaqualand and western Karoo). It is very similar to Gladiolus venustus but is less colorful with dull yellow to light brown flowers with darker yellow on the lower tepals and darker brown to purplish highlights. The dorsal tepal is also more horizontal, inclined over the stamens and the upper two lateral tepals curve outward in an arc. It is fragrant and windowed in profile. Photos 1-2 taken by Bob Rutemoeller September 2006 near Nieuwoudtville (photos 1-2). Photos 3-5 taken by Cameron McMaster in various locations near Nieuwoudtville September 2011.
Photos 1-2 taken by Bob Rutemoeller September 2006 in Namaqualand. Photos 3-4 were taken by Cameron McMaster September 2011 near Carolusberg in Namaqualand. The last two photos were taken taken by Bob Werra.
Gladiolus trichonemifolius Ker Gawl. is found on wet sandy flats in the winter rainfall areas. It flowers in late winter to early spring and is cream to yellow with brown lines on the lower tepals and a darker yellow center.
Photos below show the typical form. The first photo by Alan Horstmann, the second by Mary Sue Ittner, and the last two by Michael Mace.
This species now includes a form formerly known as Gladiolus citrinus Klatt, which has a cupped perianth and a dark purple blotch in the center. It's very different from the typical form. The first three photos from Rod Saunders and Bob Rutemoeller show the former Gladiolus citrinus.
Gladiolus tristis L. is one of the more widespread species in the winter rainfall regions. It is often found in dense colonies on damp flats, but can be found near sea level to high elevations. It is nicknamed the marsh Afrikaner and can be found in marshy areas, but also on banks above streams, in poorly drained seeps or on cool south-facing slopes. The time of bloom varies by populations. It produces a lot of little cormlets around the base of the corm and can spread to other pots if soil is reused. This species also spreads by seed, and has been known to naturalize in habitats it likes such as gardens and botanical gardens. It's not a thug, but be aware of what you're doing if you put it in the ground in a mediterranean climate. Plants grow to about 2 feet (~0.7m) tall with slender, spiraling leaves about the diameter of a chopstick. It is easily grown in a well-drained mix, full sun, and summer dry dormancy. Give it a dilute or slow release fertilizer high in phosphorous when in active growth.
Photos 1-2 were taken by Sheila Burrow, 3 by Doug Westfall, 4-5 by Alan Horstmann and 6 by Kathleen Sayce.
I grow two forms. One is light yellow and blooms March to April. It is only slightly fragrant at night. It is the first one pictured below. In the second photo there is a spider on the flowers, catching what seems to be a fly pollinator. The second form pictured below in photos 3-4 is a late blooming form, once known as Gladiolus tristis var. aestivalis, but not recognized as a variety by Goldblatt and Manning. These plants were grown from IBSA seed collected near Paarl where they grow in wet boggy areas that are shady. This form is very fragrant at dusk/night when the flowers are open wider as well. The last photo shows one corm on a 1 cm grid with all the cormlets showing how many new plants are possible from one corm. Photos by Mary Sue Ittner .
Habitat shots taken by Bob Rutemoeller September 2003 at Drayton and Cameron McMaster at Bredasdorp.
Gladiolus venustus G.J.Lewis has flowers that are shades of purple to pink and sometimes dull yellow with yellow markings on the lower half of the lower tepals. It is widely distributed across the interior of the winter rainfall areas of southern Africa where it is found in dry habitats on clay and sandstone slopes. The primary pollinators are long tongued bees. It can be confused with Gladiolus scullyi and it has been included in that species at one time but it usually more colorful than that species which is usually greenish cream to yellow brown or beige and more highly scented. The dorsal tepal on Gladiolus scullyi is also more horizontal, inclined over the stamens and the upper two lateral tepals curve outward in an arc. But the distinctions are sometimes difficult to tell, especially in areas where they both grow. An example of this difficulty is shown in the third picture which I suppose could be either species. The first two photos by Mary Sue Ittner and Bob Rutemoeller were taken September 2006 in the Roggeveld. The third photo from Mary Sue Ittner was taken near Nieuwoudtville. The last two photos were taken by Cameron McMaster September 2011 near Middelpos in the Roggeveld.
Photos below were taken by Bob Werra.
Photos below were taken by Arnold Trachtenberg.
Gladiolus virescens grows on sandstone or clay slopes in a broad area flowering in late winter to spring. Flowers are yellow to pink with dark veins and very fragrant. The first photo shows a pink one grown by Alan Horstmann and photographed by Bob Rutemoeller. The next two photos were taken by Mary Sue Ittner of plants grown from seed. Photos 4 and 5 were taken by Andrew Harvie at the De Hoop Nature Reserve. The last photo was taken by Rachel Saunders of an unusual color form found flowering in December, much later than the usual time.
Two different color forms were photographed in the southwest Cape September 2003 by Bob Rutemoeller. The next three photos taken by Cameron McMaster at Boskloof and near Napier, both in the Overberg. The last picture shows the seed pods.
Gladiolus woodii Baker grows in grassland, on rocky hillsides from 800 to 2000 m. in the summer rainfall area of South Africa from KwaZulu-Natal to the Limpopo Province. Mostly found in high elevation and high rainfall areas, it flowers early in the season, soon after it rains (from September to December). Leaves are often short and sheath the stem. Flowers are variable in color, pale yellow or lilac, oyster colored, dark maroon or red-brown with or without a longitudinal dark brown to purple stripe along the midline of the lower tepals and faintly to not scented. The upper tepals are much larger than the lower tepals and the lower laterals are folded. Photo from Rod Saunders.