Description :

• Deciduous perennials
• Rootstock a globose corm rooting from below, axillary in origin, tunics densely fibrous
• Stem aerial, usually simple, round in section
• Leaves few, lower 2 or 3 cataphylls; foliage leaves unifacial or subterete, lowermost the longest arising on stem above corm, blades linear or falcate, either with a definite midrib, or with a few prominent veins and margins thickened or not, remaining leaves arising above ground and smaller than basal
• Inflorescence a spike, flowers spirally arranged or more or less distichous when crowded, entire spike loosely twisted; bracts firm-textured, short, lax or imbricate, green below, apices dry and brown, or entirely dry
• Flowers zygomorphic with arcuate stamens, shades of blue, white or purple, lower three tepals with darker markings in lower half, unscented, usually with nectar from septal nectaries, or without nectar; perianth tube short to elongate, funnel-shaped or cylindric
• Tepals subequal, spreading or dorsal arching over stamens
• Stamens unilateral and arcuate; pollen monosulcate, operculate, exine perforate or reticulate
• Style filiform, branches deeply divided and recurved
• Capsules woody, ellipsoid to fusiform
• Seeds angular-elongate with a chalazal crest or fusiform with a long persistent funicle in one species, smooth or rugose, matte, surface areolate
• x = 10

Nomenclature:

• Thereianthus G.J.Lewis
  • Lewis: 33 (1941)
• Beilia Eckl.
  • Ecklon: 45 (1827) name only

Distribution & Notes:

• Southern Africa : Species 7, Western Cape; mostly in sandstone soils, unusual in blooming in the summer in this area of winter-rainfall

Additional Notes:

• Pollination is poorly known
• The short-tubed and nectarless flowers of T. racemosus appear to be pollinated by monkey beetles (Scarabaeidae) while the long-tubed species may be pollinated by long-proboscid horseflies (Tabanidae)