Chinese Oaks in Jungle Gardens producing acorns

The two old Chinese Oak trees located on the grassy hill near the Buddha Circle are producing acorns for the first time in three years.


I have watched these two exotic oak trees growing in Jungle Gardens now for 3 consecutive years and this is the only year during in which both trees show some serious acorn production.


Last year one of the trees, the Red Bark Oak, (Quercus gilva) did have small acorns but they never fully developed and all of them eventually aborted at a very small size. The failure to grow to any appreciable size suggested the flowers had not been suitably pollinated. That same season the nearby Bamboo Oak (Quercus myrsinifolia) showed no signs of any acorn production.


Yesterday I visited both trees and much to my surprise there is a considerable number of acorns on both trees and they are large. The acorns I saw yesterday are much larger and more numerous than any I saw last year. I don’t know what conditions might have prompted pollination but it appears both might produce a crop of nuts this year.

I will be monitoring their progress very closely.

Searching for the Rarest Plants ever found on Avery Island

June 4th, 2019

For decades I have known about the rarest of all native plants ever discovered on Avery Island, and for decades I have searched for and yet still not relocated three of these rarest species. Each was collected only once back in the 1930s and then never seen again. The plants have always intrigued me, and I have spent countless hours exploring deep ravines on the Island in hopes of locating them again. My searches have not been in vain, for I have made numerous discoveries of other rare plants, several of which had never been reported for Avery Island. But my hopes of relocating these three original discoveries have not yet materialized. This month, however, I made a special effort to track down the location of the actual herbarium specimens of these rare plants.
My first search led me to the Philadelphia Academy of Natural Sciences (PANS) where famous botanist Edgar T. Wherry (1885–1982) deposited specimens he collected from Avery Island in 1936. Wherry found two species of North American ferns new to Avery Island, the Adiantum pedatum (“northern maidenhair”) and the Diplazium pycnocarpon (“narrow-leaved glade fern”).


Both species occur elsewhere in eastern North America, including Louisiana, but are considered extremely rare throughout the southern part of their range. Their discovery on Avery Island represents the southernmost location for both species in the United States and was a range extension of about 150 miles from the nearest known locality in the Tunica Hills north of St. Francisville, Louisiana. The topography of Tunica is remarkably similar to that of the largest salt domes along the Gulf Coast: Avery Island, Weeks Island, and CÔte Blanche Island. All of these areas are riddled with deep ravines that offer a unique habitat for some of North America’s rarest native flora.
After contacting the PANS herbarium curator, I was able to acquire high-resolution images of the very specimens that Wherry collected on Avery Island. I was eager to see what notes about their discovery might be included on the label data.


Much to my surprise there are two specimens of the Adiantum. Both are mature fronds that were very fertile. This indicates that the species was apparently thriving in this location at the time it was collected. Unfortunately, the collection data is insufficient, and as such the original area where these specimens were found remains a mystery. The single specimen of Diplazium pycnocarpon is equally interesting: it is a rather large plant, though sterile. Wherry clearly indicates on the collection label that he only observed a single plant of this species. Again, the locality data on the label is quite vague: “north facing gully cooled by moving air.” Too vague to determine where he found them. Since all three specimens have the same collection date of September 9, 1936, and similarly vague habitat descriptions, I think it is likely all three came from the same location. It is equally interesting that there are no subsequent records of either species ever being collected again on Avery Island, despite the fact that other botanists are known to have collected on Avery Island in 1938, only two years after Wherry. They did not report either of these plants in their collections.


One of those other botanist who visited Avery Island in 1938 was Donovan S. Correll (1908-1983). He collected a specimen of Diplazium loncophyllum (“lanced leaved glade fern”). At that time it was the first and only record known from North America. It is a tropical species occurring in the Caribbean, Mexico, and Central America. Its occurrence on Avery Island is likely due to Gulf winds or storms that transported the spores. Correll made a single collection of this species that is on deposit in the herbarium at the New York Botanical Garden. Once again, the collection data is quite vague: “deep heavily wooded ravine, south side of Avery Island.” He does indicate that the plant is “rather abundant.” This is the only collection of this species known from Avery Island.


I located a small but thriving population of Diplazium loncophyllum on Weeks Island in the 1970s. Subsequent trips were made to this location many years later, and the plants were still thriving. In the late 1980s I finally had the opportunity to explore CÔte Blanche Island. Much to my delight on that trip I located a single small plant of D. loncophyllum. The specimen resides at the UL Herbarium (LAF).


I have searched Avery Island ravines and gullies for 45 years and have failed to relocate these three species. Nevertheless, I still have hopes of rediscovering these elusive ferns, because there are potentially many of these ravines on the Island yet to explore.

Red Buckeye – State Champion Tree

 

 

TREE IN JUNGLE GARDENS TO BE ADDED TO THE LIST OF STATE CHAMPION TREES FOR LOUISIANA

The common Red Buckeye (Aesculus pavia) is scattered throughout the southeastern United States from Texas to Florida and northward to Illinois and Virginia. It is most often a shrub or small tree.  While large trees of this species are rare, they have been reported on a few occasions, and I personally have found a few very large ones. 

One Red Buckeye in Jungle Gardens on Avery Island stands out as being exceptional. When Mike Richard Sr. of Jefferson Island showed this tree to me three years ago, I could not believe how large it was. Since that time I have searched the literature and internet for other record-size Red Buckeye trees in the United States and have not found any reported. 

Because of this tree’s size and location, I believe it is unlikely a cultivated plant but instead a naturally occurring one. The species is frequent in the forest throughout Avery Island and even occurs in woods along the island’s outer edge near surrounding cypress swamp forest. 

I contacted the state’s Forestry Service and described the tree, telling them what I thought we had on Avery Island. On February 26, 2019, Dr. Rick Williams of the Natural Resources Conservation Service, a section of USDA, came to Avery Island to check out the tree and take the required measurements.

This Red Buckeye is 40 feet tall and has a canopy of 40 feet across and a circumference of 41 inches. Dr. Williams said unquestionably it is the largest one he has ever seen, and there are none of similar size recorded in Louisiana. He is confident the State Forestry Commission will approve its listing as the State Champion Red Buckeye. Furthermore, he went on to say that since no other large ones are listed on the National Registry, he thinks it is an excellent candidate as a National Champion tree. 

NOT BAD! NOT BAD AT ALL! 

Florida Torreya – Torreya taxifolia

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Torreya in Jungle Gardens

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Torreya in Jungle Gardens

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Seed cone of Torreya

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Natural Range of Torreya taxifolia

Torreya taxifolia, commonly known as the Florida nutmeg, Florida Torreya, gopher wood, stinking yew, or stinking cedar (although not a true yew or cedar), is a very rare and endangered conifer in the yew family found in the Southeastern United States, at the state border region of northern Florida and southwestern Georgia.

The first plantings of Torreya taxifolia are now in Jungle Gardens.

Torreya taxifolia has one of the most restricted natural ranges of any native tree.  It is only known from a very small area of bluffs and ravines within Torreya State Park and at the Nature Conservancy Apalachicola Bluffs and Ravines Preserve, located along the east bank of the Apalachicola River in the northern Florida Panhandle and immediately adjacent southernmost Georgia.  It is for all practical purposes nearly extinct in its natural habitat.

The population decline is attributed to a Fusarium fungal pathogen that prevents trees from reaching a mature size, thus preventing them from producing viable seeds and may ultimately kill the tree.  The population of mature trees declined swiftly after the 1950s.  Most trees found are immature and less than 6 feet tall.  Fewer than 10 mature trees producing male or female cones are known to exist.

Fungicide treatment has been shown to be effective for fungal infection, with plants showing renewed growth after treatment.  Recovery of the species may be hindered by global warming.   It appears to be best adapted to the cooler, moister climates.  Botanist believe this tree originate much further north and was forced south in advance of the last glaciers.  Torreya produces a very large cone containing a single seed that resembles green plum.  Chances are once it arrived at its southern destination it was unable to return north in the postglacial warming, due to poor dispersal abilities of the heavy seed.

Some biologists have even suggested that Torreya taxifolia is an evolutionary oddity similar to the Avocado and Osage orange, all of which are thought to have been dispersed by now-extinct animals. The seeds of Torreya taxifolia are extremely hard and require scarification to germinate, which may have been performed by the process of passing through an animal’s digestive tract. The terpene content of the berries and the thinness of the seed’s shell imply that the extinct ecological partner may have been a large tortoise.

Torreya thrives in cultivation and is now being produced commercially by nurseries in several southeastern states.  Successful plantings of this species have been on going for many decades at botanical gardens and private estates and now there are mature trees producing seed in several locations including one at the Caroline Dorman Briarwood Nature Preserve in north Natchitoches Parish,  Louisiana.  The elevated lands of Avery Island appear to be an ideal place for establishing a grove of this rare native cone bearing tree.

Kurogane Holly : Ilex rotunda

 

The Kurogane Holly or Round Leaf Holly is perhaps the rarest of the many hollies that occur in Jungle Gardens.  Do not confuse this tree with the more common Ilex cornuta var. rotunda.  They are very different.  Only four large trees and two small ones are known to occur in the gardens. All of the large trees are female so unfortunately none of their fruits produce viable seeds.  It is one of the most attractive Holly species in cultivation, producing tremendous clusters of bright red berries in fall months.  Their dark green leaves are spineless as is the entire plant.  This evergreen tree can reach a height of 50 feet.  Those in the gardens are all of similar height, 30+ feet, suggesting they were planted at the same time.  All of these occur along Palm Garden Road.   In 2018,  two additional Round Leaf Hollies were discovered at the edge of a wooded area, not far from one of  the mature trees.  Both of these trees are near one another, both are 6 feet tall and 1 inch in diameter, suggesting they are young plants of similar age and originated from seed.   This gives hope that a male tree could exist in the area but has remained undiscovered.  Careful scrutiny of the flowers on all of the mature trees is needed in early spring to see if some of them might also be producing some pollen bearing flowers.

Kurogane holly was first described in 1784 from Japan.  This species of holly is one of the recognized Hibakujumoku trees.  Hibakujumoku is the Japanese term that refers to trees that are known to have survived the bomb at Hiroshimi in 1945.  The Kurogane Holly is also the official tree of several Japanese municipalities.