Effect of seed age and soil texture on germination of some Ludwigia species (Onagraceae) in Nigeria.

Seed germination in Ludwigia was greatly influenced by seed age and soil type. In Ludwigia abyssinica germination was not influenced by seed age and soil texture. Freshly shed seeds and six month old seeds of Ludwigia decurrens variety B showed a very low percentage germination on all the germinationmedia, and six month old seeds germinated significantly earlier than freshly shed seeds. Some soil types could significantly reduce germination of freshly shed seeds of L. hyssopifolia, L. erecta, L. leptocarpa and L. octovalvis var linearis