The classification and the relationships among the genera of Chinese
Triticeae were studied based on morphological characters with reference to geographi-
cal distribution and habitat conditions.
The spike of Triticeae might have been derived from a panicled inflorescence like
that in the Bromeae through a racemose inflorescence like the one in the Brachypodie-
ae. There might be three evolutionary lines in the tribe.
1. Pedicels of the panicled inflorescence have become short and bracts decreased
in size, which has resulted in a panicled spike with indefinite spikelets or false solitary
spikelets at each node of rachis. The middle ribes of both glumes and lemmas and ra-
chilla are not in a single plane. 2. A simple spike with usual solitary spikelets at each
node of rachis has been derived from the raceme. The middle ribe of both glumes and
lemmas and rachilla are in a single plane. 3. A cymose spike with 3-spikelets at each
node of rachis has evolved from the cymose panicle. The glume on the central spikelet
is behind the lemma, while those on the lateral spikelets are on lateral sides of the lem-
mas.
From what we have described above Triticeae may be divided into three subtribes:
Elyminae, Triticinae and Hordeinae. Then according to the morphological characters
of glume, lemma and other organs as well as the habitats and distribution, the native and
introduced triticeous plants are classified into 13 genera (Leymus, Elymus, Roegneria,
Elytrigia, Aegilops, Triticum, Agropyron, Eremopyrum, Secale, Haynaldia, Psathyrosta-
chys, Hordeum and Hystrix) and their relationships are also discussed meanwhile.