Centaurea melitensis L.
Malta thistle
Annual or biennial. Stems erect, ribbed, branched above, (10)-25-60 cm tall, with sparse to dense multicellular and cobwebby hairs. Lvs decurrent on stems, with both short curved and sparse cobwebby hairs; lower lvs oblanceolate to spathulate, toothed to lyrate-pinnatifid, 5-8 × 0.5-1.5 cm; upper lvs linear-spathulate to linear-lanceolate, becoming smaller. Capitula shortly stalked or subsessile, often clustered. Involucre broadly ovoid to globose, (6)-8-12 mm diam.; outer and middle bracts ovate, not veined, glabrescent or with sparse to dense cobwebby hairs; appendages recurved to spreading, not covering bracts, spinous, not narrowed at junction with bract, not decurrent on bract; terminal spine 6-10 mm long, pale or red-brown; lateral spines (2)-3-(4) on each side, 1-3 mm long, in (1)-2-(3) pairs at base of terminal spine, the other pair in basal ⅓ of terminal spine. Florets yellow, the outer slightly radiate. Corolla densely clothed in glandular papillae. Achenes c. 3 mm long, pubescent; pappus c. 2 mm long.
N.: Auckland, Hawke's Bay, Manawatu, Wairarapa, Wellington; S.: Nelson, Marlborough, Westland, Canterbury, Otago.
S. Europe 1891
Roadsides, riverbeds and coastal stony land, grassland, waste land, railway yards.
FL (Oct)-Dec-Feb FT Dec-May.
C. melitensis differs from C. solstitialis, the only other yellow-flowered sp. with spinous appendages in N.Z., in its glandular corolla, its lvs with short curved and sparse cobwebby but not lanate hairs, and by having 1 pair of lateral spines borne c. ⅓ of the way up the terminal spine. The 2 spp. were frequently confused in early N.Z. records.
