Four new Serruria species
John Rourke has just described four new species of Spiderheads in the South African Journal of Botany (56: 497-505).
Serruria effusa Spreading Spiderhead has been confused with Serruria cygnea Swan Spiderhead in the past, which explains why such a widespread species is being described only now. The differences between the two species are most closely tied to the method of regeneration after a fire:
The illustration in Vogts (1982: 42) has a mat-like habit and is thus S. cygnea, not S. effusa.
Serruria effusa occurs between 100 and 750 m from Lambert's Bay to Warmbaths. It can be easily seen on Grey's, Pakhuis, Elandskloof and Cardouw Passes. It flowers from August to September.
Serruria reflexa Milky Spiderhead has an erect, very sparsely branched habit; silvery-haired short leaves, almost without a stalk; heads borne on long (50-70 mm), thin stalks; and, hairless styles which reflex (bend from vertical to horizontal) after the flowers have opened. It flowers in October and is confined to the Cold Bokkeveld between Warmbaths and Porterville, at 400-800 m. It is illustrated as Plate 73 in Vogts (1982).
It can most readily be confused with the Marshmallow Spiderhead S. aitonii which is a rounded shrub; has leaves with a short stalk; heads borne on a 5-30 mm long, thin stalk; and hairless styles. The Marshmallow Spiderhead occurs from the Cedarberg to the Groot Winterhoek Mountains, as well as the west coast Sandveld and the Picketberg mountains and it flowers from July to November. So in both distribution and flowering phenology it encompasses the Milky Spiderhead.
Serruria viridifolia Mat Spiderhead has a compound inflorescence with few-flowered heads borne in panicles. It can be distinguished from other Pin Spiderheads (Fasciflorae) by its prostrate habit, forming dense mats 1-2 m wide; its vivid green, hairless leaves; and the minutely silky-haired petals in 8-10 mm heads. It is a Riviersonderend endemic, growing between 800 and 1000 m on deep sands on the north slopes. It flowers from October to November. Sue Tansley (1987) described this as "S. glabra" with the Red Data Book status of "Critically Rare".
Serruria deluvialis Grass Spiderhead has very small, stalkless, 10-14 flowered heads; a very short (7-8 mm), hairless style, and sparsely divided, hairless leaves. Even in full flower the plants are so inconspicuous that it took me five minutes to see the plants when I was standing in the middle of a dense stand! It flowers in October, and occurs in two main areas on the Palmiet River: at Arieskraal, where it has been ploughed up and flooded by dams (hence its name "of a flood or deluge"), and in the Kogelberg Nature Reserve, where it occurs in the area of overlap for all three dam configurations proposed as alternatives by Escom. This species was referred to as "S. patersonii" by Sue Tansley (1987) and has the Red Data Book status of "Critically Rare". Note that John's map does not include the southernmost population.
These four species have been included in the summary of names and getting to know Serruria (page 10). It is only a pity that the descriptions of the new species did not mention Tansley's (1987) Red Data Book status and Vogts' (1982) illustrations, even though they are irrelevant to the taxonomy of the species.
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