Herself’s Houston Garden

Plants use RNA as a way to send messages through out the plant. When a dodder vine attacks a plant some of the plant’s RNA gets sucked up by the dodder vine. The dodder vine can then read the RNA to better evaluate how to attack the host.

Professor Neelima Sinha and colleagues at the UC Davis Section of Plant Biology studied dodder vines growing on tomato plants in the lab. They found that RNA molecules from the host could be found in the dodder up to a foot (30 cm) from the point where the parasite had plumbed itself into the host.

Plants often use small RNA molecules as messengers between different parts of the plant. In a paper published in Science in 2001, Sinha’s group showed that RNA could travel from a graft into the rest of the plant and affect leaf shape. Plants can also use specific RNAs to fight off viruses. . . [ read more Plant Parasite Wiretaps Host ]

While I’d heard a fair bit about leaf miners my first run in with them came this fall on the tomatoes I planted.  You can easily identify the damage.  It looks like someone took a beige marker and drew a squiggly line all over several leaves.  They are especially fond of vegetable crops.

Leaf miners are actually fly larvea.  The feed between the top and bottom of your plant leaves on the inside of the leaf.  As you can imagine this makes it very difficult to do anything about them.

In all but extreme cases they do little damage to the crop and are not something to be overly concerned about.

leaf miner damage

I planted this vine with the greatest of hopes. It grew, and grew and every week I beat it back. Nary a single flower. Tiring of beating the vine back, I cut it down and am now trying it in a new location. Perhaps next year I’ll have some flower photos of my own?

Fast grower! Can easily reach 20′ tall in two summers.

Grows best in moist woodland areas. But must have several hours of sun for blooming.

Blooms appear early summer, flowers can be anywhere from 8″ to 20″ on older vines.

This is one of the few vines that is easier to grow from seed than from cuttings.

Aristolochia grandiflora is originally from Central America, there are about 350 species worldwide. Some grow in tropical areas others in temperate forests.

Highly toxic plant - do not ingest.

Problems:
Spider mites may attack this plant.

This is an interesting plant in that its flowers give off a scent to attract flies. Flies fly into the flower and it traps them. They fly around inside the flower getting totally covered in pollen. In the morning the flower opens allowing the pollen covered fly to escape and pollinate another flower.

Swallowtail and birdwing butterfly caterpillars use this as a food source. They absorb the toxins making them toxic to birds that would eat them. Some species of this plant are toxic to butterflies and they can get confused and lay eggs on the wrong species of Aristolochia ( elegans ). So know your species before you plant it.

One of the most fascinating things about plant and insect evolution is the defenses they mount to protect themselves from prey. Often plants or insects become toxic to the critters that eat them. Sometimes they grow to look like closely related toxic plants.

Milkweed has taken a different approach. It grows faster to better feed the caterpillars. This is great news for us monarch lovers. Monarchs have evolved to resist the toxins in milkweed. Tracing milkweed back it appears milkweed has given up on growing better hairs and more toxic latex and decided to concentrate on faster growth and repair.

The adage that your enemies know your weaknesses best is especially true in the case of plants and predators that have co-evolved: As the predators evolve new strategies for attack, plants counter with their own unique defenses.

Milkweed is the latest example of this response, according to Cornell research suggesting that plant may be shifting away from elaborate defenses against specialized caterpillars toward a more energy-efficient approach. Genetic analysis reveals an evolutionary trend for milkweed plants away from resisting predators to putting more effort into repairing themselves faster than caterpillars — particularly the monarch butterfly caterpillar — can eat them. . . . [ read more Milkweed's evolutionary approach to caterpillars: Counter appetite with fast repair]