Table 1.
Morphologically identifiable reference samples used to generate rbcL, matK, nrITS2, psbA-trnH and/or psbA-trnH mini-barcode sequences and to validate the psbA-trnH mini-barcode. Standard herbarium codes are used [41]. Cultivated specimens are indicated, all others are presumed to be wild collected. All sequences except EU531713 [42] were produced for this study.
| Species | Voucher Specimen | Locality | Sample Type | GenBank Accession | |||
|---|---|---|---|---|---|---|---|
| rbcL | matK | nrITS2 | psbA-trnH | ||||
| Dicerocaryum zanguebarium | Loeb and Koch 339 (NY) | Namibia: Oshikango | reference and validation | — | — | — | KT717163 |
| Harpagophytum procumbens | Allen 308 (M0) | Botswana: Orapa | reference and validation | — | KT717103 | KT717127 | KT717148 |
| Harpagophytum procumbens | Davidse and Loxton 6296 (MO) | Namibia: Keetmanshoop | reference and validation | KT717178 | KT717109 | KT717133 | KT717153 |
| Harpagophytum procumbens | de Koning 8142 (MO) | Mozambique: Chigubo | reference | — | KT717110 | — | — |
| Harpagophytum procumbens | Dinter 396 (MO) | Namibia: Okahandja | reference and validation | — | — | — | KT717150 |
| Harpagophytum procumbens | Grignon 239 (MO) | Botswana: Ghanzi | reference and validation | KT717174 | KT717104 | KT717128 | KT717149 |
| Harpagophytum procumbens | Hardy 6575 (MO) | Namibia: Aranos | reference and validation | KT717168 | KT717095 | KT717124 | KT717154 |
| Harpagophytum procumbens | Herman 1264 (MO) | South Africa: Blouberg Privaatnatuurreserwe | reference and validation | KT717176 | KT717107 | KT717131 | KT717151 |
| Harpagophytum procumbens | Lavranos and Bleck 22701 (MO) | Namibia: Otjiwarongo | reference and validation | KT717177 | KT717108 | KT717132 | KT717152 |
| Harpagophytum procumbens | Lavranos and Bleck 22703 (MO) | Namibia: Khorixas | reference and validation | KT717173 | KT717102 | KT717126 | KT717147 |
| Harpagophytum procumbens | Leach 10682 (MO) | Zimbabwe: Beit Bridge | reference | — | KT717099 | — | — |
| Harpagophytum procumbens | Long and Rae 44 (MO) | Botswana: Jwaneng | reference and validation | KT717171 | KT717101 | KT717120 | KT717145 |
| Harpagophytum procumbens | Ngoni 257 (MO) | Botswana: Mosu | reference | — | KT717105 | KT717129 | KY706349 |
| Harpagophytum procumbens | Owens 19 (MO) | Botswana: Deception Valley | reference and validation | KT717172 | KT717096 | KT717125 | KT717146 |
| Harpagophytum procumbens | Rodin 3539 (NY) | South Africa: Vryburg | reference | — | — | — | KY706351 |
| Harpagophytum procumbens | Rogers s.n. (MO) | South Africa: Bellville | reference | — | KT717097 | — | KY706348 |
| Harpagophytum procumbens | Sidey 305 (MO) | South Africa: Fauresmith | reference and validation | KT717169 | KT717098 | KT717119 | KT717143 |
| Harpagophytum procumbens | Skarpe S-319 (MO) | Botswana: Hukuntsi | reference and validation | KT717170 | KT717100 | KT717123 | KT717144 |
| Harpagophytum procumbens | Smuts and Gillelt 2130 (MO) | South Africa: Rooikop | validation | — | — | — | — |
| Harpagophytum procumbens | Venter 9637 (MO, NY) | South Africa: Glen Agricultural College | reference | KT717175 | KT717106 | KT717130 | KY706350 |
| Harpagophytum zeyheri | Germishuizen 00733 (MO) | South Africa: Bamboeskloof | reference and validation | — | KT717114 | KT717122 | KT717159 |
| Harpagophytum zeyheri | Germishuizen 990 (MO) | South Africa: Vaalwater | reference and validation | KT717183 | — | KT717138 | KT717160 |
| Harpagophytum zeyheri | Luwiika et al. 335 (MO) | Zambia: Lukona Basic School | reference | — | KT717116 | KT717137 | — |
| Harpagophytum zeyheri | Mashasha 111 (MO) | Zimbabwe: Victoria Falls | reference and validation | KT717179 | KT717111 | KT717134 | KT717155 |
| Harpagophytum zeyheri | Mogg 37171 (MO) | South Africa: Sandsloot | reference and validation | KT717182 | KT717113 | KT717136 | KT717157 |
| Harpagophytum zeyheri | Moyo 7 (MO) | Zimbabwe: Victoria Falls | reference | — | — | KT717118 | — |
| Harpagophytum zeyheri | Norlindh and Weimarck 5234 (NY) | South Africa: Pietersburg | reference | — | — | — | KY706353 |
| Harpagophytum zeyheri | Rodin 9140 (MO) | Namibia: Rundu | reference and validation | KT717184 | KT717115 | KT717121 | KT717158 |
| Harpagophytum zeyheri | Rushworth 110 (MO) | Zimbabwe: Dina Pan | reference and validation | KT717180 | KT717094 | KT717135 | KT717156 |
| Harpagophytum zeyheri | Yalala 300 (MO) | Botswana: Mahalapye | reference | KT717181 | KT717112 | KT717117 | KY706352 |
| Josephinia euginiae | Michell and Boyce 3144 (MO) | Australia: Nitmiluk National Park | reference and validation | — | — | — | KT717162 |
| Pedaliodiscus macrocarpus | Luke et al. TPR 73 (MO) | Kenya: Tana River National Primate Reserve | reference and validation | — | — | — | KT717139 |
| Pedalium murex | Comanor 608 (NY) | Sri Lanka: Potuvil—Panama Road | reference and validation | — | — | — | KT717140 |
| Pterodiscus auranthacus | Seydel 4135 (NY) | Namibia: Windhoek | reference and validation | — | — | — | KT717141 |
| Pterodiscus speciosus | Zietsman 4079 (NY) | South Africa: Hoopstad | reference and validation | — | — | — | KT717142 |
| Rogeria adenophylla | Seydel 4368 (NY) | Namibia: Windhoek | reference and validation | — | — | — | KT717167 |
| Sesamum indicum | Donmez 9932 (NY) | Turkey: Kula | reference and validation | — | — | — | KT717164 |
| Sesamum indicum | Nesbitt 1939 (RNG) | — | reference | — | — | — | EU531713 |
| Sesamum radiatum | Thomas 10563 (NY) | Brazil: Ilhéus | reference and validation | — | — | — | KT717165 |
| Sesamum triphyllum | Zietsman and Peyper 4061 (NY) | South Africa: Petrusburg | reference and validation | — | — | — | KT717161 |
| Uncarina grandidieri | Falk 97001 (NY) | cultivated | reference and validation | — | — | — | KT717166 |
Within Harpagophytum, variation was only observed in psbA-trnH (Figure 1, Figure A1). Harpagophytum can be unambiguously distinguished from all other Pedaliaceae by alignment positions 16, 64, and 116. The two Harpagophytum species can be differentiated by alignment positions 76 and 107. Intraspecific variation was observed in reference samples of both H. procumbens (alignment position 95) and H. zeyheri (alignment positions 77 and 88). Only one of these variants is exactly correlated with geography or current taxonomy: position 77 distinguishes H. zeyheri subsp. suboblatum (sample from Namibia) from H. zeyheri subsp. zeyheri (samples from South Africa). No samples of H. zeyheri subsp. schijffii were available for examination.