Euryops diosmiphyllus J.H.J.Vlok

Vlok, J. H. J., 2020, Three new species and one new subspecies of Euryops (Asteraceae: Senecioneae) from the Klein Karoo in the Western Cape Province, South Africa., South African Journal of Botany 133, pp. 167-173 : 169-170

3.3. Euryops diosmiphyllus J.H.J.Vlok

Euryops diosmoides B.Nord. & Vlok , ms. ( Manning and Goldblatt, 2012)

Type: South Africa, Western Cape Province, Ladismith (3320): lower northern foothills of Warmwaterberg, about 2 km east of Plattekloof house, (- DB), 540 m, 21 June 1992, J.H.J.Vlok 2641 ( NBG holo.; S, iso.).

Densely branched shrublet up to 40 cm tall, with several branches from base; young branches very densely leafy with no internodes visible. Leaves erect, appressed to stem, 1.5—2.0 x ca. 1 mm, simple, terete, obuse, somewhat carnose, glabrous with surface covered in minute white dots. Peduncles lateral in uppermost leaf axils, 12—15 mm long, terete, 0.5 mm thick. Involucre cup-shaped, 4—5 mm diam., often purple at base. Involucral bracts uniseriate, 7 or 8, glabrous, connate for half their length, triangular, 2—3 X 3 mm, 3- to 5-veined, acute-penicillate. Ray fl orets 5 to 8; corolla yellow, tube cylindrical, 1.5 mm long; lamina oblong, 4—5 mm long, 4-veined; style branches erect, 0.5 mm long. Disc fl orets 20 to 25; corolla yellow, 3 mm long; tube cylindrical, 1 mm long; limb campanulate, 2 mm long with lanceolate lobes. Anthers 1.5 mm long with ovate appendage. Style terete, branches erect-spreading, 0.5 mm long, tip papillate. Pappus bristles white, numerous, 1.5 mm long. Mature achenes not seen, ovaries of ray and disc florets papillate. ( Fig. 2 and Plate 3 ).

Flowering period: June. Plants respond to rain and flower within six weeks after rain. Flowering may thus depend on rainfall events, rather than the season.

Distribution and ecology: Euryops diosmiphyllus occurs in the Ladismith district in Succulent Karoo vegetation, more specifically in the Western Little Karoo unit sensu Mucina and Rutherford (2006). At a finer scale Vlok and Schutte-Vlok (2015) described this vegetation as Apronveld. It grows mostly on the south-west facing slopes of a small hill with sandstone and quartz rocks on the surface and with Gibbaeum pubescens (Haw.) N.E.Br. ( Aizoaceae ) prominent in the local community.

Diagnosis: Euryops diosmiphyllus belongs to the sect. Angustifoliae as pappus bristles are present on the ray- and disc-florets and the peduncles are axillary on the stems. It is most similar and probably related to E. muirii C.A.Smith , but is readily distinguished by its involucral bracts that are connate for half their length (free to the base in E. muirii ) and by the evenly sized leaves that are 1.5—2.0 mm long (2—5 mm long in E. muirii ).

Conservation notes: Despite several searches in seemingly suitable sites the species is known only from the type locality, where it is locally abundant, but restricted to an area of about 1.5 ha ( Fig. 3 ). Part of the habitat was lost when an access road was constructed through the population. Following Raimondo et al. (2009) , I propose a conservation status of Endangered ( C2 (a) (ii)) for this species.

Etymology: The specific name refers to the leaves that are very similar in size and shape to those of several Diosma L. ( Rutaceae ) species.

3.3.1. Changes to species key

This species can be accommodated in the existing key to sect. Angustifoliae ( Nordenstam, 1968: 38) by changing couplet 10 to the following:

(i) Involucral bracts connate to half their length; leaves ericoid, 2 mm long.. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...... E. diosmiphyllus

(ii) Involucral bracts not as above.. ... ... ... ... ... ... ... ... ... continue with existing key.

Figures

Plate 3. Euryops diosmiphyllus, typical plant at type locality. Photo: J.Vlok.

Fig. 2. Euryops diosmiphyllus, drawn from the type specimen. A, flowering branch; B, capitulum; C, ray floret; D, disc floret; E, anther; F, style branches of disc floret. Artist: Tin Sj¨oberg.

Fig. 3. Distribution of Euryops dasyphyllus (Z), E.bertilii (*), E.diosmiphyllus (Δ) and E.subcarnosus subsp.fallax (•). Graphics: A.Schutte-Vlok.