Ruschia aristata L.Bolus

Klak, Cornelia, Hanáček, Pavel & Bruyns, Peter V., 2023, Six new species of Ruschieae (Aizoaceae) and further notes in Ruschia, South African Journal of Botany 156, pp. 144-161 : 157

1 Ruschia aristata

L.Bolus was transferred to Erepsia Section Crassifoliae , as Erepsia aristata (L.Bolus) Liede & H.E.K.Hartmann , on account of several similarities with this section of Erepsia ( Hartmann, 1998) . Striking similarities with Erepsia include the multi-locular fruits (i.e., with (9-)10 (-13) locules), the absence of closing bodies and petals which curve over the centre of the flower ( Hartmann, 1998). Typical features of Ruschia are fruits with 5 (-6) locules and small closing bodies and flowers where the filamentous staminodes are gathered around the stamens into a central cone. However, several species in Ruschia associated with subg. Cymbifoliae , also lack closing bodies. In R. aristata the uppermost parts of the placentas are detached and form open hoods, whereas in Erepsia the upper portions of the placentas are not detached. In R. aristata the flowers are solitary and showy (to c. 30 mm diam.) and their many filamentous staminodes curve over the centre of the flower. Notably, there is no hypanthium in R. aristata ( Fig. 16 ). The presence of a hypanthium 0.7-2 mm high is a diagnostic feature for Erepsia ( Liede, 1989) . The notable absence of a hypanthium in R. aristata appears to have been overlooked when this species was transferred to Erepsia ( Hartmann, 1998) . Furthermore, this species is only found in the Eastern Cape ( Fig. 7 ). This contrasts strongly with the restriction of all other species of Erepsia to the south-western Cape ( Liede, 1989) and also casts doubt on whether R. aristata is correctly placed in Erepsia .

Ruschia joubertiniana (see above) and also R. staminodiosa L.Bolus share the “odd” flowers and fruits with R. aristata , except that in R. staminodiosa the fruits are 5-locular ( Hartmann, 2017c). Our molecular phylogeny places these three species in one clade with other members of Ruschia (Klak et al., in prep.), which shows that loculenumber may range from 5 to 12 in some clades of Ruschia . This is similar to the range of locules observed in Erepsia (5-13 locules, Liede, 1989) or even in smaller genera such as the bitypic Hartmanthus S.A. Hammer (where the fruits have either 5 or 8-10 locules, Hammer and Hartmanthus, 1995). We therefore re-instate Erepsia aristata in Ruschia and place it in subg. Cymbifolia .

Ruschia aristata L.Bolus , Notes Mesembryanthemum 2: 369 (1932),

Erepsia aristata (L.Bolus) Liede & H.E.K. Hartmann , Bradleya 16: 64 (1998).

Lectotype (selected by Hartmann 2017: 566): Harcourt-Wood 235 ( BOL 45918, barcode: BOL132173 ) .

3.2.6. Additional collections investigated

South Africa. EASTERN CAPE: 3325 (Port Elizabeth): Uitenhage div., Groendal (-CB), Sep. 1939, J.R. James ( BOL) ; 27 Feb. 2021, L. Strydom 9 ( BOL) ; Chases Kloof (-CB), 4 Dec. 1974, E. Blake s.n. ( BOL) .

Figures

Fig. 16. Illustration of Ruschia aristata. Artist:B. Carter.

Fig. 7. Distribution of species of Ruschia subg.Cymbifoliae. R.joubertiniana (triangle), R.knysnana (circle) and R.aristata (star).