Pollination ecology of Merremia tridentata (L.) Hallier f. (Convolvulaceae)

Merremia tridentata is a twining and prostrate herb. The flowers are campanulate, bisexual, weakly protandrous, self-compatible and facultative autogamous. The forager guilds indicate that thripsophily, melittophily and psychophily are functional pollination syndromes. Ballistichory, anemochory and hydrochory are the seed dispersal modes. Seeds germinate as soon as they reach the ground if the soil has sufficient moisture or else they remain dormant and germinate during the rainy season. Such seed dispersal modes and flexible germination responses enable the plant to invade and colonize new areas. Further, the plant with perennial woody root stock stays alive during the dry season, sprouts back to life during the rainy season to re-start its life cycle. The dual modes of regeneration enable the plant to form extensive herbaceous cover and bind the soil effectively. Therefore, the plant is an important soil binder and useful at controlling soil erosion.

Effect of Eight Container Types and Root Pruning During Nursery Production on Root Architecture of Acer rubrum

There is a general understanding that roots deflect when striking solid nursery container walls, and that on trees with good vitality this occurs within weeks of shifting into larger containers. Root architecture is poorly understood when observed in containers with walls constructed of porous plastic and of materials other than plastic. The objective of this study was to measure impacts of container type, root pruning when shifting to a larger container, and cardinal direction on root architecture in nursery containers up to the #45 size (approximately 170 L). Trunk diameter in #45 containers varied less than 5 mm among eight container types and was not impacted by root pruning. More root growth occurred in the northern than southern half of containers. Container type had a small impact on root architecture; in contrast, root pruning by shaving the periphery of the root ball at each shift had a large impact. Shaving when shifting dramatically reduced the percentage of trees graded as culls and suppressed stem-girdling root formation compared to not shaving. Shaving shifted deflected woody root mass from the interior of the root ball to the exterior, making it simple to remove peripheral roots when planting into the landscape.