In late 2012 in Systematics of the Hypervariable Moraea tripetala Complex, by Goldblatt & Manning, Bothalia 42, 2. , Moraea tripetala was divided into nine species and three varieties, based on genetics, plant anatomy, and flowering time. Species generally have dark to light blue or purple flowers; small or missing inner tepals; and flower in the winter to spring. To identify the tripetala relatives, you'll need to know how to recognize some moraea flower parts:
One shared characteristic of the tripetala "complex," as it's now called, is a small or completely missing inner tepal. The inner tepals are the three inner petals of the Moraea flower, corresponding to the standards in an Iris. The tiny fishhook-shaped appendages in the center of the photo below are the inner tepals of one of the tripetalas.
Much attention is also paid to the nectar guide, the contrasting color spot found on the outer tepals (the large petals, corresponding to the falls in an Iris). This is usually white or yellow in these species. Iris fanciers call this spot the signal, but moraea growers sometimes call it the eye.
Other distinguishing characteristics include leaf anatomy and length, number of leaves, corm anatomy, and shape and size of other flower parts. We haven’t given all of those details here. If you need them, read the article linked below.
The descriptions we give here were adapted from the Goldblatt, Manning article.
Flowers with threadlike, hair like or missing inner tepals
Moraea amabilis Diels - Flowers purple or dark blue, but occasionally pink, yellow, or brown in populations near Worcester. Nectar guides white with purple speckles. Inner tepals hair-like, under 2.5 mm. The parent corm is usually replaced annually by two daughter corms that split off and descend at roughly a 90-degree angle to one-another. Blooms September - October. Photos from iNaturalist taken by Nick Helme in August in the Cederberg and September in the western Cape and Gregory Nicolson in Worcester and shared under a CC BY-NC license. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flowering stems and corm; B, inner perianth whorl plus filaments and style; C, capsules; D, seeds. Scale bar: A, C, 10 mm; B, D, 2 mm.
Moraea grandis Goldblatt & J.C.Manning - Largest flowers in the tripetala complex, pale blue to pale purple. Nectar guides are triangular, yellow or cream, on a white background, and are spotted and edged in dark blue. Inner tepals hairlike, under 3.5 mm. Pollen orange-red. Blooms August to September. Grows in the northwestern Karoo. Photo from Mary Sue Ittner taken near Nieuwoudtville.
Moraea ogamana Goldblatt & J.C.Manning - Pale blue, triangular yellow nectar guides with dark lines radiating from them. Inner tepals threadlike, under four mm. White pollen. Often has a cormlet in the leaf axil. Western Cape lowlands. Blooms Aug-Sept. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flowering stem; B, capsules; C, seeds. Scale bar: 10 mm.
Moraea tripetala (L.f.) Ker Gawl. is widespread in the western Cape where it grows in a variety of soils. Plants grow from 20 to 45 cm tall, usually with a solitary leaf and with pale blue, purple, or violet flowers with triangular nectar guides, yellow edged with violet, or white dotted with dark blue and edged with darker blue. They have small or missing inner tepals and flower winter to spring (occasionally later.)
Moraea tripetala ssp. tripetala - Pale blue to purple flowers. Nectar guides are usually white dotted and edged with dark blue, but occasionally are yellow. Inner tepals are usually hair-like and under five mm long, or may be completely absent. Pollen red or white. Has a single leaf. Blooms August to October. Reportedly does not reproduce by cormlets in the wild. Drawing by John Manning shared with his permission from the paper referenced above. Photo by Cameron McMaster. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flowering stems and corm; B, C, inner perianth whorl plus filaments and style; D, seeds. Scale bar: A, 10 mm; B–D, 2 mm.
Moraea tripetala ssp. violacea Goldblatt & J.C.Manning - violet flowers with yellow nectar guides. Relatively short plants. Stiff hair-like inner tepals around 2 mm in length, pollen white. Ceres to western Karoo. Blooms August to October. Photo from iNaturalist taken by Marion Maclean in August and September in the Little Karoo and shared under a CC BY-NC license.
Flowers with variable inner tepals (7-20 mm long)
Moraea cuspidata Goldblatt & J.C.Manning - Pale blue, mauve, or violet flowers, large white fuzzy nectar guides. Dark violet dots in the nectar guides and often on the outer tepals. The inner tepals are linear (thicker than a thread, but straight-sided) and usually over 10 mm long. Pollen usually red. Blooms mid-September to late October. This is an inland species from arid mountain areas. Photo from iNaturalist taken by Dave U in the Central Karoo in September and shared under a CC BY-NC license. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flowering stems and corm; B, inner perianth whorl plus filaments and style. Scale bar: A, 10 mm; B, 2 mm.
Moraea decipiens Goldblatt & J.C.Manning - Pale to deep purple flowers with a white wedge-shaped nectar guide and a dark violet stripe above it. The inner tepal widens in the middle so it almost divides into three points. Pollen is orange-red. Plants grow in the western Piketberg and bloom in late October.
Moraea mutila (C.H.Bergius ex Eckl.) Goldblatt & J.C.Manning - Pale blue or white flowers, nectar guides white to pale yellow with dark blue or purple spots. Inner tepals are more or less linear, or may widen into rounded lobes midway along their length. Pollen red or yellow. Blooms late August to late September. Grows from the Cape peninsula north to Piketberg and east to Tulbagh. Photo from iNaturalist taken by Jacques van der Merwe in the western Cape in August and shared under a CC BY-SA license. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flower; B, capsule; C, seeds. Scale bar: A, B, 10 mm; C, 2 mm.
Flowers with variable inner tepals (1-6 mm long)
Moraea hainebachiana Goldblatt & J.C.Manning - Pale violet to deep blue flowers. Nectar guides have dark lines and dots on a diffuse white background, with dark lines radiating onto the tepals. Inner tepals expanded in the middle. Blooms August to September. Grows cormlets in the leaf axil and at the base of the parent corm. This species does not set seed, and its pollen appears to be infertile. It apparently reproduces through cormlets. (This was the first plant in South Africa named via auction to raise money for plant conservation.) Photo from iNaturalist taken by kooscl late August in the Western Cape and shared under a CC BY-NC license. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flowering stems and corm; B, inner perianth whorl plus filaments and style. Scale bar: 10 mm.
Moraea helmei Goldblatt & J.C.Manning - Pale blue to violet flowers. The outer tepals have dark veins on them. The nectar guide is yellow, outlined in light or dark blue. The inner tepals have three straight tines, like a fork. Pollen is yellow. Known from only two sites in central Namaqualand. Blooms late October to mid-November. Photo from iNaturalist taken by Nick Helme in October in the Kamiesberg and shared under a CC BY-NC license. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: A, flowering stem and corm; B, inner tepal; C, inner perianth whorl plus filaments and style. Scale bar: A, 10 mm; B, C, 2 mm.
Moraea tripetala ssp. jacquiniana (Schltr. ex G.J.Lewis) Goldblatt & J.C.Manning - Looks similar to typical M. tripetala, but usually dark violet, and always with white nectar guides. Inner tepals are 4-6 mm long, pollen red, blooms in early summer (November to January). Photo from iNaturalist taken by Nick Helme in November in the Western Cape and shared under a CC BY-NC license. Drawing by John Manning shared with his permission from the paper referenced above. Figure notes: Scale bar: 10 mm.