Gymnodiscus Less.
Creators: name: Magoswana, S. L.
name: Boatwright, J. S.
name: Magee, A. R.
name: Manning, J. C.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Asterales
Asteraceae
Gymnodiscus

description: Gymnodiscus Less.
in Linnaea 6: 95 (1831); Syn. Comp. 89 (1832); Benth. & Hook.f. in Gen. Pl. 2: 452 (1883); Harv. in Harv. & Sond., Fl. Cap. 3: 345 (1865); Anderberg et al. in Kubitzki., Fam. & Gen. Vasc. Pl. 8: 237 (2007).
Type: G. capillaris (L.f.) DC.
Annual, rosettiform herbs to 40 cm, branching from base, crown and sometimes leaf axils cobwebbed; with slender taproot. Leaves rosulate, prostrate or spreading to suberect-recurved, either fusiform and succulent, or obovate–spathulate to oblanceolate or lyrate–pinnatifid and coriaceous, often purple on reverse or mottled purple, mucronulate. In fl orescence subscapose, peduncles one to several from crown, branched above, sometimes with lateral peduncles from the axils of leaf-like cauline bracts, upper inflorescence bracts small, linear to cordate. Capitula heterogamous, radiate, in small corymbose or sub-umbellate clusters, aggregated into compounded paniculate synflorescences. Involucre campanulate to sub-globose, ebracteate [ecalyculate], bracts uniseriate, 5 or 8(9), free, lanceolate to elliptic, glabrous, margins scarious, green with darker apices. Receptacle conical, punctate, glabrous, epaleate. Ray fl orets female-fertile, 5 to 9, yellow, limb elliptic-ovate; ovary ellipsoid to obovoid, glabrous or appressed-puberulous with twin-hairs; style terete, with slightly thickened base, branches with discrete lateral stigmatic areas, apices narrowly obovate and shortly papillate. Cypselas ellipsoidovoid, 0.8–1.5 mm long, 5-ribbed, dark brown, glabrous or densely appressed-puberulous with white twin hairs; pappus of short, basally united, barbellate bristles one quarter as long as cypsela, persistent, white. Disc fl orets functionally male, few to many, yellow, perianth tube funnel-shaped, 5-lobed, lobes spreading; anthers obtuse at base with ovate apical appendage, filament collar balusteriform; ovary narrowly ellipsoid, glabrous; style simple, cone-tipped; pappus lacking.
Diagnosis: rosettiform annual herbs with scapose peduncles bearing small, ecalyculate capitula in small corymbs or subumbellate clusters; involucral bracts 5 or 8(9); ray florets female-fertile, pappus of short barbellate bristles; disc florets male-fertile with undivided, cone-tipped style, pappus lacking.
Distribution and ecology: 2 spp., endemic to the Greater Cape Floristic Region of South Africa, usually on sandy flats or gentle slopes in sandy soils.
Key to species of Gymnodiscus
1a. Leaves obovate–spatulate to oblanceolate or lyrate–pinnatifid, leathery, often purple on underside; ray florets with perianth tube short (0.3–0.5 mm long) and style well exserted from tube and branching above it; ray ovaries and cypselas puberulous. G. capillaris.
1b. Leaves terete-fusiform, succulent, glaucous; ray florets with perianth tube longer (1.0– 1.5 mm long) and style included and branching just below mouth of tube; ray ovaries and cypselas glabrous. G. linearifolius.
description: Published as part of Magoswana, S. L., Boatwright, J. S., Magee, A. R. & Manning, J. C., 2016, A taxonomic revision of Gymnodiscus (Asteraceae: Senecioneae: Othonninae), a Greater Cape Floristic Region endemic *, pp. 71-77 in South African Journal of Botany 106 on page 72, DOI: 10.1016/j.sajb.2016.05.017, http://zenodo.org/record/10496398