Hydnora visseri

Hydnora visseri
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Magnoliids
Order: Piperales
Family: Aristolochiaceae
Genus: Hydnora
Species: H. visseri
Binomial name
Hydnora visseri
Bolin, E.Maass, & Musselman[2]

Visser's Hydnora (Hydnora visseri) is a subterranean holoparasitic plant, lacking leaves and roots, and is described from southwestern Namibia and northwestern South Africa and has the longest tepal lobes of all Hydnora species. The genus Hydnora is composed entirely of holoparasitic plants that attach to the root of their hosts and are restricted to Africa and SW Asia.

Introduction

Visser's Hydnora as a holoparasitic plant, lacks chlorophyll and depends entirely on its hosts, Euphorbia gregaria or Euphorbia gummifera for all water and nutrition. The pollination of Visser's Hydnora involves a trap and release mechanism where dermestid beetles are detained for several days then released dusted with pollen.[3]

Description

Hydnora visseri lacks leaves and roots. The vegetative body of the plant is a brown warty rhizome that spreads laterally through the soil. The bumps on the rhizome of Hydnora spp. can differentiate into haustoria (specialized organs for parasitizing the host plant), flower buds, or bifurcations of the rhizome. The rhizomes when broken are reddish to pink and contain high levels of tannins.[4] The only portion of the plant that emerges from the soil surface is the large fleshy flower. The fruit a large berry with thousands of small (< 1mm diameter) seeds is usually buried or just at the soil surface.[5]

Taxonomy

In South African and Namibia where Hydnora visseri may be encountered, four other Hydnora spp. exist, H. abyssincia, H. africana, H. longicollis, and H. triceps.[6] Visser's "Hydnora" can be discriminated from those taxa by its exclusive hosts E. gummifera and E. gregaria and by having the longest tepals of any Hydnora spp. in Southern Africa, 5.5–9 cm long.[5] The family Hydnoraceae has been submerged within the Aristolochiaceae in the Piperales based on a modern phylogenetic study that also found that the plastome of Hydnora visseri is highly reduced, relative to photosynthetic plants, only 27K base pairs.[7]

Distribution and habitat

Hydnora visseri is present in Succulent-Karoo and Nama-Karoo vegetation types and the winter rainfall and transitional rainfall areas of the Karas Region of Namibia and the Northern Cape Region of South Africa in a limited distribution centered around the Orange River and it is only present where its hosts Euphorbia gummifera and Euphorbia gregaria are present.[5][1] Hydnora visseri is most easily located by searching in around the base of the host Euphorbia plants.

Etymology

Hydnora visseri is named after Stellenbosh University Professor Johann H. Visser (1931-1990) and author of the text South African Parasitic Flowering Plants.[5]

Conservation

Based on the Red List of South African Plants H. visseri is considered a taxon of Least Concern due to its widespread distribution in regions with large protected areas such as the Ai-Ais/Richtersveld Transfrontier Park and Sperrgebeit National Park.[1]

Ethnobotany

Other Hydnora spp. are known to be available in Southern African herbal markets in Mozambique[8] and South Africa.[9] In South Africa the Imbola yesiXhosa are reported to use a thin paste of the powdered Hydnora rhizome as a treatment for acne and other skin conditions.[10] In Uganda, the Hydnora spp. are reported to be used as food (fruits) and medicine (rhizomes) for diarrhea, hypertension, and diabetes,[11] though these claims have not been confirmed.

References

  1. 1 2 3 "Red List of South African Plants". SANBI. Retrieved 2 November 2016.
  2. "International Plant Names Index". Retrieved 2 November 2016.
  3. Bolin, Jay F.; Maass, Erika; Musselman, Lytton J. (February 2009). "Pollination Biology of Hydnora africana Thunb. (Hydnoraceae) in Namibia: Brood‐Site Mimicry with Insect Imprisonment". International Journal of Plant Sciences. 170 (2): 157–163. doi:10.1086/593047.
  4. Tennakoon, K. U.; Bolin, J. F.; Musselman, L. J.; Maass, E. (1 September 2007). "Structural attributes of the hypogeous holoparasite Hydnora triceps Drege & Meyer (Hydnoraceae)". American Journal of Botany. 94 (9): 1439–1449. doi:10.3732/ajb.94.9.1439.
  5. 1 2 3 4 Bolin, Jay F.; Maass, Erika; Musselman, Lytton J. (1 June 2011). "A New Species of Hydnora (Hydnoraceae) from Southern Africa". Systematic Botany. 36 (2): 255–260. doi:10.1600/036364411X569453.
  6. Kalassen, Esmerialda; Kwembeya, Ezekeil. "A CHECKLIST OF NAMIBIAN INDIGENOUS AND NATURALISED PLANTS" (PDF). NBRI: Occasional Contributions No. 5. Retrieved 7 November 2016.
  7. Naumann, Julia; Der, Joshua P.; Wafula, Eric K.; Jones, Samuel S.; Wagner, Sarah T.; Honaas, Loren A.; Ralph, Paula E.; Bolin, Jay F.; Maass, Erika; Neinhuis, Christoph; Wanke, Stefan; dePamphilis, Claude W. (February 2016). "Detecting and Characterizing the Highly Divergent Plastid Genome of the Nonphotosynthetic Parasitic Plant (Hydnoraceae)". Genome Biology and Evolution. 8 (2): 345–363. doi:10.1093/gbe/evv256.
  8. Williams, V. L.; Falcão, M. P.; Wojtasik, E. M. (1 April 2011). "Hydnora abyssinica: Ethnobotanical evidence for its occurrence in southern Mozambique". South African Journal of Botany. 77 (2): 474–478. doi:10.1016/j.sajb.2010.09.010.
  9. Williams, V. L.; Wojtasik, E. M.; Witkowski, E. T. F. (2011-04-01). "Ethno-ecological evidence for Hydnora abyssinica occurring in Johannesburg and Durban traditional medicine markets". South African Journal of Botany. 77 (2): 268–279. doi:10.1016/j.sajb.2010.08.005.
  10. Dold, Tony. "Imbhola yesiXhosa Traditional Xhosa cosmetics". Veld and Flora. September: 123–125.
  11. NYAFUONO, JANE F.; BUKENYA, REMIGIUS Z.; ODYEK, OLWA (2000-01-01). "Taxonomy and Ethnobotany of Hydnora in Lake Mburo National Park (uganda)". Israel Journal of Plant Sciences. 48 (2): 99–103. doi:10.1560/NQBR-UN7F-464G-19WJ. ISSN 0792-9978.
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