Saturday, December 28, 2024

AMARYLLIS (the plant), not the amphipod!

There are only two known species of plant with its beautiful flowers. The plant is native to the western Cape region of South Africa, in the rocky area betwwen the Oligants River and Knysna. Amaryllis has been introduced into California (see images below), Great Britain, Australia, and New Zealand.


Its classification is:


  Kingdom Plantae

  Order Asparagales 

  Family Amaryllidacea

  Genus Amaryllis Linnaeus, 1753

  Species: only two species are known.


The common names of this plant are “belladonna lily,” “Jersey lily,” “armarillo,” “Easter lily” (in southern Australia), and the “March lily” (in South Africa). These plants, however, are only distantly related to the true lily, Lilium


The name “Amaryllis” symbolizes “love, beauty, and determination.” The plant is up to 3 feet tall, with long leaves. Its flowers are large and funnel shape, and have long stems. The flowers can be white, pink, apricot, rose, or deep burgundy. The images shown below are from plants grown in my garden in northern Los Angels County, Southern California.





This plant normally flowers in late summer. It is NOT frost tolerant, but it does not like tropical environments. It likes considerable shade (but not total shade) and does not like to “sit” in water.  It does well is the Los Angeles area.


While researching this flower, I was surprised to learn that the genus name “Amaryllis” is used also for a group of marine crustaceans (amphipods) that live in shallow oceans (depth from shoreline to 50 m) in the western Indian Ocean! This is allowed in the long-standing rules of taxonomy (= the naming of organisms) because the name “Amaryllis” applies to both plants and marine animals; otherwise, one name or the other would have to be changed.

Reference consulted: Wikipedia

Sunday, December 22, 2024

MEDITERRANEAN CYPRESS: A TREE WITH MANY NAMES

This evergreen-conifer tree has many synonyms. Examples are the following:  Cupressus sempervirens = [“Mediterranean cypress” a.k.a  "Italian cypress"], "Tuscan cypress," "Persian cypress," “pencil pine," “tiny towers,” and/or “green spine.” 


This kind of tree tapers quickly (thus it is pencil shaped). It is a very narrow (4 to 5 feet wide) tree, but it can be very tall (commonly reported as up to 115 feet tall (= 35 m). These kind of trees rapidly increase their height (about 2 to 3 feet per year), but eventually their growth rate slows down. Their roots are primarily vertical and usually not disruptive to nearby walls. In my neighborhood in southern California (northern Los Angeles Count), there are quite a few localized stands of the "Mediterranean Cypress." The tallest ones are about 80+ feet tall (estimated height) or more, as they have been growing for many decades.

A cluster of this cypress in Southern California, with a telephone pole, for scale. I estimate this cluster to be at least 70 feet tall.

The foliage of this type of tree consists of clusters of short needles on upright branches. Shown is a cluster, 7 inches long, 5.5 inches wide.

A view showing only the uppermost 10 feet of a cluster of these trees. Their seed cones are located only in the uppermost part of each plant.


This plant does not flower, but in the late summer and fall, it produces small, roundish, green to brown (can be copper color) seed cones, which are initially closed--but open up somewhat later. Shown here are representative seed cones from the upper part of the tree. The cones are about 1.5 inches in height and ¾ inch in diameter.


Shown above is a dried-up and cracked seed cone, ¾ inch height and by ¾ inch in diameter. Dried cones are used for crafts and decorations. The cones are tightly held together at first, but eventually, they fall apart.

The fossil record of this genus is poorly known. The geologically earliest known occurrence of Cupressus in the rock record is Oligocene in age (very approximately 30 million years old) in South China (Shi, G. et al., 2011). A Paleocene fossil of Cupressoconus from Britain is probably an earlier representative of genus Cupressus (Shi et al, 2011).


References Cited or consulted


Belger, T.J. 1984. Roadside plants of southern California. Mountain Press Publishing Co., Missoula. 157 pp.


Shi, G. and others, 2011. Cupressus foliage shoots and associated seed cones from the Oligocne Ningming Formation of Cuangzi, south China. Review of Palaeobotany and Palynology 166(3):325-334. (free pdf available online)


Watts, T. Desert tree finder. Natural Study Guild. 61 pp. [note: an inexpensive “pocket

book” for hikers].

Wednesday, December 11, 2024

WINGS? ON A GASTROPOD SHELL

Can wings can be present on a snail snail? The answer is, of course not!  But, this post concerns the so-called “winged triton” seashell, more formerly known a Gyrineum perca. In scientific description, these so-called “wings” are more properly referred to as varices. They are aligned  along the sides of the shell, and they probably provide stability on the ocean floor for the shell. The growth of varices on shells is referred to as “episodic,” growth; that is to say, it is intermittent but fast. Initially, a thin-flexible expansion of the shell is built, and as this material is secreted, it is mineralized and gradually thickened, over a period of several days. The gastropod otherwise remains inactive and concealed until the new shell material is hardened (Vermeij, 1993). 

For you “old timers,” this particular seashell was colloquially known as the “winged triton” or “maple-leaf triton.” For awhile, it was previously referred to in the scientific literature as Apollon perca or Biplex perca, but if you regularly read my posts, you will be fully aware that the names of sea-shells are commonly in a state of flux these days; mainly, because of new DNA data about these animals.

A

B


C

Gyrineum (Biplex) perca, length 55 mm, width 45 mm, thickness 16 mm.apertural view. A) apertural view. B) abapertural (back) view. C. Right-side view. No Locality data available.



Another specimen of Gyrineum perca: length 52 mm, width 40 mm, thickness 15 mm. This second specimen has an operculum [used to close off the aperture from predators]; the operculum consists of horny [=organic material which is not calcified]. Locality data not known.


According to WoRMS [World Register of Marine Species], the current classification of this seashell is:


Class Gastropoda

Order Littorinimorpha

Family Cymatiidae

Genus Gyrineum

Subgenus Biplex

Species perca (Perry, 1811)


The shell of Gyrineum (Biplex) perca ranges from 31 to 100 mm (1.2 to 3.9 inches) in length. The shell, which is white, yellowish, or pale brown, is quite flattened, with a large flange (“so-called wings”) along its two sides.


The modern-day distribution of Gyrineum (Biplex) perca is eastern Africa to Japan. It is essentially  confined to warm (tropical) waters (Wikipedia, 2024). 


Gyrineum is one of the 24 known genera of family Cymatidae Link, 1807. To view some of the species of Gyrineum that resemble Gyrineum perca (there are at least four other such species)—the differences being in the shape of the wings (flanges); for more information, see the following website: https://www.jaxshells.org/gryrineum.htm 


References Cited:


Beu, A.G. 1998. Family Ranellidae. In Mollusca The Southern Synthesis, Part B. Fauna of Australia Volume 5. Pp. 799-802. CSIRO Publishing, Melbourne, Australia 


Vermeij, G.J. 1993. A natural history of shells. Princeton Science Library. 207 pp.


Wikipedia. 2004.


WoRMS. 2024. World Register of Marine Species [https://marinespecies.org]


Tuesday, December 3, 2024

AN UNUSUAL SOUTHERN CALIFORNIA ORB-WEAVER SPIDER

Spiders, like other arthropods, have six legs. This blog post concerns a species of spider belonging to the order Araneae, family Araneidae, and genus Argiope (the orb-weaver spiders).


Orb-weaver spiders are the most common group of spiders in the world. Some of them can be bizarre-looking and very brightly colored. I recently found two specimens in my garden. Compared to other orb-web spiders found in southern California, they are unusual. Their bodies (carapaces) have a yellowish-brown color pattern. The exteriors have several rows of prominent bumps that protrude out over the ventral surface.


I checked what literature I have in my natural-history library, as well as online, and I determined that these spiders represent an unusual variety of Argiope argentata, a species that typically lives in New World tropical and temperate regions, especial in of Central America and South America. The specimens in my garden, however, have a less spectacular color pattern than most other Argiope argentata species, which can have patches of silver, black, red, yellow, green, orange and/or brown.


A

                                            

Dorsal view of specimen (A): length of spider approximately 2 inches long). Next, below, is the ventral view (B) of this same specimen (slightly out of focus). The prominent white, “zig-zag thread” = the stabilmentum, which was secreted by the spider. See the text for a discussion of the function of the stablimentum. [Note: this kind of spider positions itself upside down on its web. The wind was blowing when I took this picture, and I could not get a sharp-focus image of ventral (bottom side) of this spider].

B 


The last and third image (C), see below, is a ventral view of another, but smaller, specimen (length only1.25 inches). Its stabilmentum is also present (on the left side of this view). The web of this specimen was more complete than the other specimen. Both specimens were found in my garden, in northern Los Angeles County, southern California. 


C
                               

Orb spiders typically have very large and complex orbicular (circular) webs. The web of the first spider photographed above (images A and B), was only a very partial one (i.e., a small lenticular-shaped remnant of its recently damaged web). I returned the next day to view the spider, again and it and the web were gone, except for a few filaments. Orb-weaver spiders are known to routinely destroy their own webs and create new ones. That is most likely the best  explanation for the sudden disappearance of its web. The web of the second specimen was a more complete (but still small) classic orb-spider web. 


Like other orb-web spiders, the ones found in my garden positioned themselves upside down in their web where they wait for their prey (e.g., mosquitoes) to get trapped.


note: a comment on the purpose of the stabilmentum. Some experts speculate that it is to make the web visible to birds that might otherwise fly into the web and, thereby, destroy it. This type of structure is commonly made by orb spiders.


Sources of Information:


Conrad, J. 2014. A blog site. Naturalist Newsletter. https://backyardnature.net


Levi, H.W. and Levi L.R. 1968. A guide to spiders and their kin. A Golden Nature Guide, New York, 160 pp.


Nicky Bay. Orb-weavers (Araneidae checklist)-Macro photography of many species, some with unbelievable shapes and colors). An online website.