Origin of name:

interjacens = intervening, coming between;  alluding to a possible hybrid origin

Diagnostic characters:

Large individual flower heads
Straw-coloured bracts
Compact-branched inflorescences on short stalks
Leaves linear, margins inrolled, tipped

Description:

Bushy perennial herb or subshrub c. 600 mm tall, much branched from the base, branches long, thin, brittle, thinly white-woolly, closely leafy. Leaves mostly 15-20 x 2-2.5 mm, diminishing upwards and becoming more distant below the heads, linear-lanceolate, acuminate, base broad, half-clasping, eared, margins more or less revolute, upper surface cobwebby-woolly, lower more densely so. Heads heterogamous, campanulate, 3 x 1.5-2 mm, many in compact corymbose panicles. Involucral bracts in 5 series, graded, imbricate, inner about equaling flowers, light straw colour, tips obtuse, semi-pellucid, crisped, minutely radiating. Receptacle with fimbrils much exceeding ovaries. Flowers 13-25, 9-17 female, 3-8 homogamous. Achenes 0.75 mm long, cylindric, obscurely ribbed, glabrous. Pappus bristles many, equaling corolla, scabridulous, bases cohering by patent cilia.

Flowering in March and April.

Distribution:

Favours crevices in rock outcrops. Recorded from Mpumalanga on Long Tom Pass (2530CA), at Lochiel (2630BB) and the farm Rusfontein, Wakkerstroom district (2730AB), Mbabane in Swaziland, Itala and Ngome in Northern KwaZulu-Natal (2731CB and CD).

Grassland Biome.

Notes:

H. interjacens may be of hybrid origin between H. melanacme and H. polycladum: it is known from only a small geographical area where the ranges of these two species overlap, and may grow in close proximity to one or both of its putative parents. It closely resembles H. melanacme in general facies, but is readily distinguished by female flowers in a head far outnumbering homogamous; also, where these two species have been recorded together, H. interjacens has decidedly paler involucral bracts than H. melanacme. H. polycladum is easily distinguished from both by its much narrower leaves and white involucral bracts.

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Taxonomy:

Literature:

Helichrysum interjacens Hilliard in Notes R. bot. Gdn. Edinb. 40: 256 (1982).

Type:

KwaZulu-Natal, Ngotshe distr., Itala Nature Reserve, c. 1 525 m, in damp cracks in rock domes, 4 iv 1977, Hilliard & Burtt 10021 (NU holo.; E; K; MO; S, iso.).

Synonym(s):

Vouchers:

Compton 27730 (BM; M; NBG; NU; PRE); 25786 (NBG; PRE); Devenish 1696 (E; NU); Hilliard & Burtt 9852 (E; K; NU; PRE; S).