Jacobsenia hallii

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Jacobsenia hallii

Jacobsenia hallii L.Bolus, Notes Mesembryanthemum 3: 329. 1958 sec. Klak & al. 20181 wfo-0001293238
  • ≡Drosanthemum jacobsenii G.D.Rowley in Natl. Cact. Succ. J. 33: 8. 1978 syn. sec. Klak & al. 20181 wfo-0000656925
      • Type: "South Africa. Western Cape, Komkans (3118AA), 50 miles N of Vredendal, 3rd Sept. 1955, <i>H. Hall sub NBG 405/54</i> (BOL, holo!)." [fide Klak & al. 20182]
  • 1. Klak, C., Hanáček, P. & Bruyns, P. V. 2018: A recircumscription of Jacobsenia (Aizoaceae): Re-instating Drosanthemopsis, with two new quartz-endemics from Namaqualand, South Africa and sinking Knersia. – South African Journal of Botany 116: 67-81, 2. Klak, C., Hanáček, P. & Bruyns, P. V. 2018: A recircumscription of Jacobsenia (Aizoaceae): Re-instating Drosanthemopsis, with two new quartz-endemics from Namaqualand, South Africa and sinking Knersia. – South African Journal of Botany 116: 67-81

Content

Diagnosis

Jacobsenia hallii has a compact habit, lacking the characteristic long shoots found in J. kolbei. The epidermis of the leaves is covered with large bladder-cells, which each have a single central hair-like protrusion.A

Conservation

Jacobsenia hallii is a rare species, known from
only two localities and has been listed by Raimondo (2009) as vulnerable (VU).A,B

Description

Compact shrublets to 15 cm high, main stem in old plants procumbent, adult plants without clear distinction between long shoots and short shoots; each stem mostly developing 2 leaf-pairs per season; leaf-pairs occasionally slightly anisophyllous. Leaves often slightly curved, moderately spreading, mostly terete with upper surface flattened, lower surface slightly keeled, 30–70 mm long, 8–10 mm diam.; epidermis with large, ± circular bladder cells with a single central hair-like protrusion. Flowers emerging from the connate portion of the 2nd leaf-pair of the season, 80–85 mm diam., pedicels 10–20 mm long; sepals 6, two outer ones opposite, the remaining spirally arranged; petals white or light yellow; filaments deep yellow. Fruit shape of capsule seen from above 6-angled, 8–17 mm diam., locules mostly 6, rarely 5, 7 or 8.A

Citation

Ihlenfeldt, H.-D. 2017: Dicrocaulon, Diplosoma, Jacobsenia, Meyerophytum, Monilaria, Oophytum. – In: Hartmann, H. E. K., Illustrated handbook of succulent plants. Aizoaceae, ed. 2. – Berlin: Springer. p 690

Bibliography

A. Klak, C., Hanáček, P. & Bruyns, P. V. 2018: A recircumscription of Jacobsenia (Aizoaceae): Re-instating Drosanthemopsis, with two new quartz-endemics from Namaqualand, South Africa and sinking Knersia. – South African Journal of Botany 116: 67-81
B. Raimondo, C. et al. 2009: Red List of South African plants 2009