Description from Flora of China
Aralia sect. Pentapanax (Seemann) J. Wen; Hunaniopanax C. J. Qi & T. R. Cao; Parapentapanax Hutchinson.
Trees or shrubs, evergreen or deciduous, sometimes epiphytic, hermaphroditic or andromonoecious, unarmed. Leaves pinnately compound, rarely simple; leaflets entire to serrate; stipules absent. Inflorescence a terminal panicle of umbels, heads, or racemules, glabrous or pubescent, developing from specialized floral buds, usually surrounded by numerous persistent bracts at base. Pedicels articulate below ovary. Calyx minutely 5-dentate. Petals 5(-7), imbricate. Stamens 5(-7). Ovary (3-)5(-7)-carpellate; styles united into a column or divided, as many as carpels. Fruit a drupe, globose to ellipsoid or ovoid. Seeds as many as carpels; endosperm uniform.
The first author finds it hard to accept Wen’s point of view (see following paragraph), in which Pentapanax was treated as a section of the genus Aralia, and instead recognizes Pentapanax as distinct from Aralia on the basis of three main morphological differences: (1) inflorescences developing from specialized floral buds that are usually surrounded at the base by numerous persistent bracts (vs. from mixed buds, not surrounded by bracts at the base); (2) plants woody and unarmed (vs. woody and usually prickly, or herbaceous); and (3) leaves 1(-3)-pinnate (vs. leaves usually 2-4-pinnate).
Several phylogenetic studies have shown, however, that Pentapanax forms a group that is clearly nested within Aralia (Wen, Brittonia 45: 47-55. 1993; Wen, Edinburgh J. Bot. 58: 183-200. 2001; Wen et al., Acta Bot. Yunnan. 24: 557-568. 2002). The most recent revision (Wen, Cathaya 13-14: 1-116. 2002) treated the members of this group as a section within Aralia, an interpretation favored by the second author.
Between 18 and 22 species: restricted to Asia, especially the Sino-Himalayan region; 16 species (nine endemic) in China.