Description:

• Compact or densely tufted shrublets, 150 mm high; stems to 10 mm diameter; adult plants either with erect shoots with elongated internodes and distinct lateral short shoots with very short internodes, or with ± compact habit without clear distinction between long and short shoots
• Leaves opposite, succulent, at least last leaf pair of season persisting on stem until next season; leaf pairs of a season isophyllous, leaves of a pair sometimes slightly anisophyllous, each stem usually developing 2 leaf pairs per season; leaf pairs basally connate for ± a fifth of their length, leaves erect or spreading, ± digitiform, often ± curved, upper surface sometimes flattened, lower surface sometimes somewhat keeled; the very base of the connate portion of a leaf pair developing into a narrow, ring-shaped, persisting, sclerotic sheath, usually brown-red; leaves to 70 mm long, 10 mm in diameter; epidermis with bladder cells
• Flowers terminal, emerging towards end of season from connate portion of 2nd or sometimes 1st leaf pair, solitary, pedicellate; pedicels 10-70 mm long, up to ± 80 mm in diameter; opening in morning, closing in evening
• Sepals (4)5 or 6(-8), 3 with membranous margins
• Petals 4- or 5-seriate, acuminate, white to lemon yellow, or rarely purplish, inner petals shorter
• Stamens: filaments white or yellow, papillate; pollen reticulate, spinulose; staminodes 0-very few
• Nectary a finely crenulate, ± 5-angled ring
• Ovary: placentas parietal; stigmas 5, subulate
• Fruit a 5-locular capsule, of Mitrophyllum type; closing bodies 0; valve wings broad, recurved; expanding keels diverging, margins toothed, ending in awns; covering membranes covering a half to three-quarters of locule
• Seeds globose, brown to light brown, testa minutely papillate
• x = 9

• Flowering in spring to early summer

• Distinguishing characters:
  • Shrublets with long, erect branches bearing inflorescences
  • Leaves of a pair forming plant bodies only in juvenile stage
  • Flowers white, on long, red-brown, bare stems

Nomenclature:

• Jacobsenia L.Bolus & Schwantes emend. Ihlenf.
  • Bolus & Schwantes, in Bolus: 255 (1954)
  • Bolus & Schwantes, in Schwantes: 69 (1954)
  • Herre: 180 (1971)
  • Ihlenfeldt: 109 (1997)
  • Smith et al.: 142, 236 (1998)
• Anisocalyx L.Bolus
  • Bolus: 385 (1958)
  • Herre: 72 (1971); not of Hance ex Walp., 1852 (Scrophulariaceae)
• Drosanthemopsis Rauschert
  • Rauschert: 555 (1982)

Distribution & Notes:

• Southern Africa: Species 3, southwestern Namaqualand in the vicinity of Vanrhynsdorp and Vredendal, Northern and Western Cape