On Saturday July 16, 2011, the tender age of seven months, my first and only Hibiscus martianus rewarded seven months of effort by producing two flowers which are 2 inches in diameter. The Hibiscus martianus is in a pot which can be brought in for the winter and stands 18 inches tall as of mid July.
A DG member from Austin TX, kindly sent me a large number of Hibiscus martianus seeds in early December 2010. Using seed nicking and the Deno Method two seeds in the first test batch of 10 seeds germinated. After that first success, I was unable to germinate any Hibiscus martianus seeds no matter what I did. The seeds appeared to be non-viable and were quickly consumed by fungus. I have read that it is better to work with fresh, newly harvested seeds of this species and intend to put that advice to the test if I am able to obtain mature seeds from my Hibiscus.
Of the two seedlings which were produced, the one which germinated in 2 days failed. The second seedling, which took two weeks to germinate, survived and flowered for the first time on Saturday July 16, 2011 at the age of 7 months. This Hibiscus continues to grow vigorously and more flowers are on the way.
I photographed the Hibiscus martianus in the early afternoon and then hand pollinated both flowers using a disposable Qtip to encourage maximum seed production. In the early morning the five stigmas are upright encouraging external pollination. By the afternoon the five stigmas bend downward to make contact with the anthers to insure self-pollination as a last resort. I have observed the same pollination strategy in another Texas native, Hibiscus coccineus, suggesting that native pollinators may be in short supply, with sufficient frequency, to make this a useful survival strategy. This self-pollination strategy is not found in other North American Hibiscus species which depend of external pollinators. By the late afternoon, the two Hibiscus martianus flowers neatly folded close, completing that phase of the plantís life cycle.
Once the petals are shed on the pollinated flower, the sepals close about the developing seed pot and it is almost impossible to tell if the sepals are guarding a flower bud or a seed pod without peeking. In the North American hardy Hibiscus species, the sepals only guard the flower bud and remain open after pollination. I have notices similar behavior in other hot climate Hibiscus, suggesting that the sepals are protecting the developing seed pods is such environments.
If my Hibiscus martianus makes it through this summer, I intend to bring it in the house for the winter. Even I am not foolish enough to think or hope that this Hibiscus can survive through a northern New Jersey winter.
There is some confusion as the scientific name for this Hibiscus species. While most authorities identify it as Hibiscus martianus, some continue to identify is as Hibiscus cardiophyllus. If you want to do any research on this Hibiscus you must conduct searches using both names. The popular name remains the Heartleaf Rosemallow.
Hibiscus martianus is a member of Hibiscus section Bombicella. For all the species in this section for which chromosome numbers have been determined the count is 2n=22. Additional information on this section can be found here:
This morning, Sunday July 24, 2011, two more Hibiscus martianus flowers bloomed and the Hibiscus is shown here in profile. The seed pods from July 16, 2011 have grown quite large but are still being protected by the sepals. I again hand pollinated the flowers in the hope of achieving maximum seed production. Over a half-dozen developing buds are now visible on the Hibiscus.
As the attached photograph shows, the baby continues to grow larger every day and produced three flowers on Friday which were immediately pollinated. The success rate with hand pollination appears to be 100% and I now have eight seeds pods at various states of development and more flowers are on the way. Perhaps the baby is inspired by the iconic view of the New York City skyline 9 miles to the east. Others who have grown Hibiscus martianus have not reported such a short duration from seed to flower. On the other hand, perhaps 12 hours of direct summer sunshine a day might just have more to do with it.
I would like to increase the genetic diversity of my Hibiscus martianus and locate plants which are more cold tolerant. Other species from Hibiscus section Bombicella could offer rich opportunities for the production of interesting hybrids, if the chromosome count is 22 for the entire section, so we should be vigilant for any matchmaking opportunities.
Thank you for introducing me to Hibiscus martianus.
If I obtain viable seeds in a month or two, I will let you know. You will have to raise the Hibiscus as a houseplant for the first winter but after that it should be OK in your Zone. I have been thinking about using a modified Deno Bag to send seedlings through the mail but I have to workout the process.
On August 1 the Hibiscus martianus produced four flowers (see attached), followed by one more flower two days later. I am not even photographing anything with less than three flowers any longer but I continue to hand pollinate. Obviously your Texas Hibiscus are happy in New Jersey; if they had to pay our taxes their view of the Garden State might be a bit different.
In the upper left cornet of the attached photograph you can see part of one of the Hibiscus calyphyllus you smuggled relocated out of Texas on my behalf, which is now several time larger than the Hibiscus martianus. Now I have a bit of sad news for you. The two Hibiscus calyphyllus with buds didnít flower because they were pregnant with seed pods, which looked like buds. This is the same phenomena I observed in Hibiscus martianus. The first seed pod opened before I realized what was going on and the seeds were lost. I save the seeds from the second pod. I split the seeds with a friend out west and successfully germinated three plants which are growing vigorously and are approaching the size of the original the plants you sent me. Flower buds are developing on the original plants and I should have flowers by the later part of August. I have pollen sources lined up for the crosses we discussed. I will post more on this once the flowers open.
One of the DG members sent me a DM asking where Hibiscus martianus could be found in the wild. That was an excellent question and I should have included that information in my original post. Hibiscus martianus is only found in Texas and Mexico. Here is a map for Texas: