Seriphium passerinoides Lamarck (1783: 271)

Koekemoer, Marinda, 2016, A monograph of Stoebe and Seriphium (Gnaphalieae, Asteraceae) in southern Africa and neighbouring islands, Phytotaxa 242 (1), pp. 448-450 : 448-450

6. Seriphium passerinoides Lamarck (1783: 271) . Stoebe passerinoides (Lamarck) Willdenow (1803: 2408) . Type:— FRANCE (overseas department). La Réunion, Plaines des Cafres, Commerson s.n. (P-LAM!, holotype; P-JU 8483!, P!, isotype).

Vernacular name: ‘Branle blanc’, referring to the silver sheen of the leaves.

A much branched, prostrate or upright shrub, up to 2 m tall. Branches erect or spreading, densely or sparsely tomentose. Leaves on the main branches variable, mostly linear-subulate, 2–3 mm long, involute, imbricate or just touching the leaves above; tightly adpressed, spreading on lower branches; tips mucronate but sometimes obscurely so; resin cavities present at the base of the leaves; adaxial surface densely woolly; abaxial surface villous when young but soon becoming glabrous, except at the base; leaves on young vegetative shoots often much larger, up to 8 mm long, adpressed or spreading, very closely spaced, tips acute, the dark abaxial surface contrasting strongly with the white-woolly adaxial surface; leaves of the short floral shoots much smaller, obtuse and adpressed, but otherwise similar to the leaves on the main shoots. Synflorescences terminal, up to 15 cm long; a complex arrangement of brachyblasts with solitary capitula. Capitula 1-flowered. Receptacle stalk-like. Involucral bracts 6–10, transition from green leaves to bracts gradual, innermost bracts light brown, scarious, margins winged, upper adaxial surface woolly, about as long as the floret, tip acute. Disc florets bisexual, a little over 3 mm long, purplish brown, widening very slightly from the base upwards; corolla lobes small erect, triangular. Stamens 5, apical appendages lanceolate, basally tailed. Style bifid, branches longer than the corolla, base bulbous at maturity. Nectaries absent. Cypselas 5-ribbed, scabrid. Pappus setae 16–19, plumose from the base, basally fused, a little shorter than the corolla. Flowering April to June.

Distribution and habitat: —Restricted to a few areas of high-altitude heathlands but locally very common, on the island of Réunion. On the Plaine des Cafres it is co-dominant with three to five other species, including two Helichrysum and one Erica species. In this area, west of the active volcano, the vegetation is sparse and Se. passerinoides forms a low-growing shrub with adpressed silvery leaves. On the slopes of the mountains above the town Cilaos, the growth form resembles that of Elytropappus rhinocerotis in South Africa, but Se. passerinoides shrubs are not so compact and much taller (up to 2 m); the leaves are longer, spreading and greenish. Figure 15 .

Ecology: —High elevations, 1500–3000 m, in heathlands, on volcanic soils, in areas where no lava flows have been reported since 1931. At lower elevations it is often found on disturbed soils on road verges, and also on unstable scree slopes.

Conservation status: —Least Concern.

Notes: —The Gaudichaud specimen in G shows one branch, that is strikingly similar to Se. cryptophyllum from Madagascar; the other branch on the same sheet has the leaves further apart and the branches densely woolly. In the mountains above Cilaos the author found plants that have adpressed leaves on some branches and spreading leaves on others, or even with leaves spreading in the lower part of the branch and adpressed in the upper part.

Additional specimens examined:— REUNION. Ile de la Reunion ; entre Deux , Dimitile , Crê de la Grande Jumenti forêt leg rement dégradée à tr. dégradée par endroits (21º06’S 55º36’E), 20 December 1989, Attië 6 (P); Reunion , Cilaos. Frequent everywhere at high alt. (21º07’50’’ S, 55º28’05’’E), May 1983, Williams 3441 (NBG); Plaine des Cafres , heathland (21º13’15’’ S, 55º33’36’’E), 15 November 1967, Barclay 462 (Fl. Reunion nr. 12746) (K); Plaines des Cafres , heathland type vegetation (21º13’15’’ S, 55º33’36’’E), 15 November 1967, Barclay 463 (K); Plaine des Cafres , East side (21º13’15’’ S, 55º33’36’’E), 16 November 1967, Barclay 511 ( Flora of Reunion nr. 12756) (K); Reunion , Plaine des Cafres (21º13’15’’ S, 55º33’36’’E), Boivin (K); Reunion , Le Volcan ( Massif de la Fournaise ) at Pas de Bellecombe ; high altitude heathland (21º13’44’’ S, 55º40’24’’E), 8 March 1979, Lorence 2512 (K); Reunion , Plaine des Sables , old lava flows, c. 2000m. Prostrate silvery shrublet rooted between lava pieces (21º13’50’’ S, 55º38’58’’E), 10 May 1976, Coode 5181 (K); Reunion, Per viam de Col de Bebour , 1370m alt. ad Plan des Palmistres. Frutex ramosus, scoparius, pallide glaucus, capitulis unifloris veteribus, 21 October 1973, Bernardi 14515 (PRE, K, BM, G); Reunion, haute vallee de la Riviere Langerin —arbuste dans vegetation preforestiere— 1500m, 10 May 1976, Cadet 5394 (K); Arbuste de 1m, Rochers au pied du Piton Cabri, au lessous de Ameie Aique de Mafate , 600m, 14 May 1976, Cadet 5417 (K); Ile de Bourbon , Commerson (G); Insul Borboniea, 1845, Garnier 99 (TCD); Ile de Bourbon, Sur la Bonite 1836–37 (Voyage de la Bonite, juillet 1937), Gaudichaud (K, G); Isle Bourb., Bory de et Vincent, Herb. de Ventenat (G); Reunion, 18 July 1875, M. Gaudichaud 309 (K); Bourbon, 1820, Perrottet (G); Ile Bourbon, Sieber (G) :

STOEBE AND SERIPHIUM ( GNAPHALIEAE )

Figures

FIGURE 15:—Known distribution of Seriphium passerinoides in Réunion.