STUDIES OF THE POLLEN MORPHOLOGY AND TAXONOMY OF THE TRIBES LOTEAE AND CORONILLEAE (PAPILIONOIDEAE LEGUMINOSEAE) .3. CORONILLA L AND RELATED GENERA AND SYSTEMATIC CONCLUSIONS

The pollen morphology of 48 taxa has been studied with light and elect ron microscopy. The pollen is three-zonocolporate, elliptical or more or less rectangular, sometimes circular, in equatorial outline and cir cular or triangular in polar outline; small or medium size, PxE=(14-30 )x(9-26) mu m The colpi are long, the endoapertures lalongate. The orn amentation is perforate, microreticulate, granulate-verrucate, striate -rugulate perforate-granulate or finely granular. Exine is 0.5-2 mu m thick at the mesocolpium. The endexine thickened at the equator, thinn er at the poles, the foot layer very thin or absent, the infratectum c olumellate; the columellae are sometimes almost granular often widely spaced with expanded bases and the tectum thick Ornamentation is the p rimary basis for the division into types. Five pollen types are recogn ised With the exception of Securigera, which has similar pollen to Cor onilla, the types correspond well with the genera recognised in the gr oup. The pollen morphology of Scorpiurus is distinct from that of the rest of the group. Pollen morphology is discussed in relation to the t axonomy of the group and its significance to relationships and evoluti on of the tribes is considered. It is concluded that there is little e vidence from pollen morphological studies to support the separation of the Coronilleae and Loteae as two tribes. It is suggested that the gr oup Loteae shows some affinities in pollen morphology with tropical tr ibes as for example Phaseoleae as well as with temperate herbaceous tr ibes.