作 者 ：Liou Liang
期 刊 ：植物分类学报 1988年 1期
Keywords:Panicoidese, Supertribe, systematics, Evolution,
Abstract:
Subfam. Panicoideae consists of 230 genera and 3000 species, about 1/3 of the
total number of Gramineae.
The evolution in Gramineae (Poaceae) is considered to have been proceeding in the direc-
tion of simplification. Three major lineages in Panicoideae are recognized based on analysis
of characters, geographical distribution and ecological preferences. They are represented res-
pectively by three supertribes i.e. Panicatae, Andropogonatae and Maydatae. The first supertribe
has well-developed florets, fertile lemma indurate, but is awnless and thus is the primitive
group in the subfamily. In the second supertribe spikelets are well-developed, the lower
glume is larger than the florets and embraces them, the florets are awned. Particularly signi-
ficant is the evolution of spikelets from solitary to paired, from the two spikelets of each pair
both bisexual and alike in form to heterogamous pair of spikelets in which the sessile one is
fertile and the pedicelled one sterile and further to homogamous pair of spikelets at base of
inflorescence. In this lineage occurs an inflorescence protected by a large sheathing bract. It
is the most flourishing by developed evolutionary branch. In the third supertribe raches are
developed, thick, inflorescences have become pillar-shaped with spikelets sunken in the raches.
The reduction of spikelets from bisexual to unisexual has taken place and they occur on se-
parte inflorescenes, bringing about subsequent sexual differentiation of inflorescences. Raches
have also evolved from solitary to united. The supertribe Maydatae is likely to be one of the
most advanced group in Gramineae.
Subfam. Panicoideae occurs in the tropics and subtropics, and these three supertribes have
apparently followed three lines of development under different environmental conditions. The
supertribe Panicatae adapts to hot moist conditions, the supertribe Andropogonatae adapts to
a monsoon climate, occurring in savannas, the supertribe Maydatae occurs in monsoon moist
conditions.