Systematics of Balanophora subgenus Balania (Balanophoraceae)

Balanophoraceae is a root parasitic plant without chlorophylls. Balanophora is the largest genus in Balanophoraceae, which had been divided into two subgenera, Balanophora and Balania. The first phylogenetic analysis of Balanophoraceae showed that, the agamospermic B. japonica is confirmed to be allied to B. laxiflora, which was treated under subgenus Balania taxa. In addition, the subgenus Balania species formed a monophyloetic clade with a high support. However, only two Balanophora subgenus Balania taxa B. tobiracola and B. harlandii from Taiwan in previous study were sampled, and others members such as like B. fargesii, B. involucrata, B. subcupularis and population of B. harlandii in China were not included. The aims of this research are to study the phylogenetic relationships of subgenus Balania with more complete sampling, and also to examine their micro-morphological (spadicle top surface and female flower adhering area) and palynological characters. The results from phylogenetic analysis and different micro-morphological characters, phenology and attitudinal distribution showed that B. harlandii samples is polyphyletic. According to their morphology and phylogeny, the separate bracts and diecious Balanophora harlandii should be treated as B. harlandii, B. mutinoides and a unknown species B. sp.. B. fargesii and B. involucrata are bracts sheath-like taxa formed a highly supported clade, and micro-morphological characters also showed high similarity, but due to their different sexual expression, we treated its as different taxa. Balanophora subcupularis is obviously different from all other subgenus Balania taxa by its micro-morphological characters, and the result of phylogenetic tree showed that B. fungosa it is sistered. Hence, B. subcupularis should be restated and treated under the subgenus Balanophora. In this study, we redefine the characters of two subgenus. Male flower 3-merous, pollen inaperture in subgenus Balania, male flower 4-merous above, pollen aperture in subgenus Balanopohra. In addition, we applied DNA barcoding technique to identify the host of Balanophora. According to the result, the confirmed hosts of B. mutinoides is Cleyera sp. (Pentaphylaceae), the host of B. harlandii is Callerya sp. (Fabaceae), the host of B. sp. is Hydrangea sp. (Hydrangeaceae), the hosts of B. fargesii include Acer sp. (Sapindaceae), Berberis sp. (Berberidaceae), Rhododendron sp. (Ericaceae) ,Salix sp. (Salicaceae), Schisandra sp. (Schisandraceae), the host of B. involucrata belongs to Oleaceae, the host of B. subcupularis are Acer sp. (Sapindaceae) and Celastras sp. (Celastrasceae).