275. BIARUM DITSCHIANUM Peter Boyce The genus zyxwvut Biarum comprises 21 species of tuberous-stemmed perennial herbs distributed from central Portugal to western Iran. In nature they occur usually in areas subjected to a hot, dry summer. Most species produce foul-smelling, deep purple to brownish inflorescences of which the most conspicuous element is the expanded spathe limb. A notable exception to this inflorescence type is found in Biarum ditschianum Bogner zyxw & P.C. Boyce, illustrated here. Biarum ditschianum was first collected in spring 1987 in south- western Turkey by Friedrich Ditsch, a student at Bonn University, Germany. A single tuber was cultivated at Bonn and flowered in May that year but unfortunately the plant died soon after flowering and no voucher specimen was preserved. Attempts to re-collect the species in October 1987 failed but in April 1988 Manfred Koenen of Bonn Botanical Garden succeeded in locating it and re-introduced it to cultivation. The plants flowered at Bonn in May 1988 and, from these, herbarium vouchers and specimens in spirit were prepared; these subsequently formed the basis for a description of this previously un-named species (Bogner & Boyce, 1989). Biarum ditschianum has an extraordinary appearance in flower compared with most other Biarum species. The spathe limb is reduced to a narrow rim on the spathe tube and the most notable feature is the relatively massive, dark yellow spadix appendix. Two other Biarum species have unusual inflorescences; B. dauisii {Turrill, 1938; Boyce, 1987) has pinkish white spathes, a purple spadix appendix and produces a sweet, not foul, odour at anthesis, while B. auraniticum (Mouterde, 1966) has a greenish white spathe and a yellow spadix. The odour produced by the inflorescence of the latter is unknown. Both of these species lack a zone of sterile flowers (pistillodes) on the interstice separating the male and female flower zones, a characteristic which is also true of B. ditschianum. Perhaps the most unusual feature of B. ditschianum is the presence of hair-like processes on the base of the spadix appendix. Such structures are otherwise unknown in the genus and are uncommon in the Araceae; their function is not clear, although it is possible that they play a role in the pollination process. The inflorescence is also notable for being exceptionally foul smelling and produces a powerful odour of carrion and excrement which attracts carrion flies. 141 zy 0 zyxwv Hrntham-hloxan zyxwvutsrqponm 'Trust zyxwvutsrqp 1995. Publishd by Blackwell Publishers, I08 Cowlcy Road, OxCird 054 l,JF, lJK and 23R Main Strret. Carnhridxe, MA 02142, USA.