HOLLYHOCKS: AN UNFORGETABLE PLANT WITH BEAUTIFUL FLOWERS 

They have big flowers (the ones I photographed can be up to 5 inches in diameter). The ones illustrated herein belong to genus Alcea, but there are reportedly many other "genera" and, at least, 80 or so species in this genus. Hollyhocks are apparently native to Europe and Asia. The single species found in the Americas is invasive and belongs to a different genus. I could not find any papers dealing with the details of the fossil record of hollyhocks. It is likely that Alcea [in the broad sense] originated during the Pleistocene.

Hollyhocks can be tall plants. The tallest plant I photographed (Figure 1 and Figure 4) is 11.6 feet tall (I measured it with a tape measure when the plant finally stopped growing vertically and started to dry up during the first week of July). Then in late July and even into early August, it produced a few new blooms (near the middle of the plant and at its former top).

[note: In the published literature (both written and electronic), hollyhocks are reported as having a maximum height of only 8 feet.]

Kingdom Plantae

Order Malvales

Family Malvaceae

Genus Alcea [the main genus)

Type Species: rosea

This flower is biennial or perennial, meaning they can “come back” every year. They are also self-seeders. In their first year, they grow a rosette of flowers. In the second year, they regrow and flower. They are pollinated by bees, butterflies, and hummingbirds. Hollyhocks are easy to grow. They like the sun and well-drained soil. The upper part of some hollyhock plants can (but not always) lean or bend over. 

Like nearly every other species of flower, hollyhock flowers have wide range of colors, from white to red, pink, yellow, or orange.

Figure 1. Closeup of a red hollyhock flower.

Figure 2. Closeups of two other red flowers.

Figure 3. Closeup of a pink hollyhock.

Figure 4. Tallest individual plant of hollyhock (11.6 feet tall) that I have seen.

EXAMPLES OF FLOWER GENERA: (PART 1 of SEVERAL TO COME)

At the beginning of 2025, I started taking pictures of every interesting looking flower that I saw in my garden, as well as any that I saw in my neighborhood and in nearby parks. I also visited several local nurseries and took images of every flower that looked interesting. To say the least, it was a steep-learning curve for a person who studied fossils, rocks, and minerals for most of his life and who generally ignored flowers. THERE ARE SO MANY DIFFERENT FLOWERS. Now, however, I greatly appreciate the diversity, and I am constantly taking images of new ones. Thus, I can say that I honestly like learning new things.  

I relied heavily on my wife’s vast knowledge of plants and flowers. Also, the internet proved to be invaluable tool in identifying some the new plants that I encountered. I never went on private property, except, with permission, on a few rare exceptions. I thank those property owners who gave me permission to trespass. They were always friendly, even though some they probably thought I was slightly unhinged. 

In this post and several that follow, I have selected (it was not easy!) some of the new flowers I “discovered.” 

                                          HIBISCUS

Most hibiscus flowers were derived from eight ancestral varieties that were originally native to tropical eastern Asia. The Hibiscus flower has petals that overlap one another in a circular pattern. Today, there are numerous cultivated [i.e., cultivars] found in nurseries throughout the world. An image of Hibiscus is on the National emblem in South Korea. It is also the state flower of Hawaii.

This flower can be an annual (short-lived) or a perennial (long-lived). It can be found on small trees, up to about 15 feet tall. It likes full sunlight. Its large lowers attract bees, butterflies, and humans. Its flowers can be white, red, pink, blue, orange, peach, or yellow.

Like most flowers, it is speculated that Hibicus evolved from an ancestral form about 135 million years ago, when Gondwanaland broke up from Pangea.

Each hibiscus flower has both male and female parts. The ovary of the flower lies in the main structure in the center of the hibiscus flower. The pistil is long and tubular. The five “hairy” red structures at the top of the pistil make up the stigma, which is where the pollen is collected. Bracts are leaf-like structures positioned beneath a flower. Brachs are NOT petals of a flower. For those who want to know, its flowers exhibit the solitary cyme kind of inflorescence.

                               

Three color varieties of Hibiscus. Each of these flowers shown above is about human-hand size.

Classification

Order Malvales

Family Malvacease

Genus Hibiscus

Type Species H. rosa sinensis [which has a large and conspicuous trumpet-shaped flower]. Linnaeus, who named countless species of flowers and animals, also named this flower.

Note:  There is a single Hibiscus small tree (about 15 feet tall) in my neighborhood. Since early spring of this year (2025), it has had numerous blooms on it. And, now that it is August, it is still blooming (mostly at the top of the plant).

EARLIST FLOWERS

EARLIEST FLOWERS ARE GEOLOGICALLY OLDER THAN MANY DINOSAURS

                                  Earliest Known Fossil Flowers

Angiosperms are plants that have male and female reproductive parts and also bear their seeds in fruit. The earliest known angiosperm fossil is Montesechia vidalii, approximately 130 mya [i.e., million years ago] (= Early Cretaceous time) from Spain (Gomez et al, 2015). Today, angiosperms are the most diverse group within Kingdom Plantae and represent 80% of all living green plants.

Figure 1. Early Cretaceous fossil of Montesechia vidalii, 60 mm long. This weed-like plant had no roots and was probably an ancient aquatic angiosperm plant.

The next evolutionary “step” in flower evolution was Archaefructus liaonigensis, approximately 125-130 mya (Early Cretaceous) from northeastern China. This  angiosperm plant, which is one of three species of this genus, probably lived in a lacustrine environment (i.e., lake or pond).

Figure 2. Early Cretaceous fossil of Archaefructus, less than 50 cm (20 inches) tall) with simple roots. It was most probably an aquatic angiosperm species with two types of flowers: one bearing pollen (yellowish in the figure shown here) and one bearing reproductive structures (grayish in the figure shown here). This plant most likely lived in lacustrine (lake) or pond environments.

                                                  Water lilies

Water lilies (family Nymphaeceae) are perennials that live in fresh water at depths between 6 and 15 feet. Although these plants are rooted in soil in the bodies of water, their leaves and flowers float or rise above the surface. The leaves are oval to heart shaped and are fully circular or can have a slit (short radial notch). The edges of the leaves can be smooth or serrated. 

The leaves have hollow air-filled  channels (tubes) in their stems that provide buoyancy. The flowers, which can be any color—but commonly white) have unspecialized reproductive parts. Recent generic studies confirm that the evolutionary position of water lilies to be basal angiosperms. Only 2% of angiosperms are aquatic today.

The flowering season of water lilies is May through September. These plants propagate via rhizomes that allow the plant to spread into interconnected aquatic habitats. They live in temperate and tropical areas around the world. They are represented by five genera and approximately 70 species. 

Water lilies now provide the critical link in the evolution of flowers. This statement is based on modern genetic studies that have helped confirm that water lilies, with their unspecialized reproductive parts, have a basal position among flowering plants.

Several fossil species of water lilies are known—mainly of Cretaceous age from Brazil.

Figure 3

Figure 4

Figures 3-4. Water lilies in the early part of their “blooming time.” Images kindly provided by Lindsey Groves, Collections Manager at the Natural History Museum of Los Angeles County, southern California.

Note: Although water lilies resemble lotus flowers, they are not the same. Interestingly, botanists are now recognizing the floral and vegetative similarities between the lotus and sycamore trees (see one of my previous posts regarding the latter plant) (Alka, 2007).

                                         Magnolia Tree 

The oldest known flowering tree is Magnolia, which originated approximately 100 Ma to 95 Ma. This tree co-existed with some dinosaurs of that time. Magnolias evolved before bees evolved and, therefore, had to rely on beetles for pollination. The flowers of the magnolia tree are generally now regarded as being primitive, mainly based on the relative positions of the female (pistils) and male parts (anthers) within the flowers. Also, magnolia leaves are relatively unspecialized.

                                               Figure 5

Figures 5-9. The image directly above and the next four images are all from the same Magnolia tree, which is located in northern Los Angeles County, Southern California (note: most Magnolias are most common in the southeastern part of the United States). Although Magnolia trees can be up to 80 feet tall, the tree figured here is only about 45 feet tall. 

                                                                        Figure 6

Close-up view of the previously shown Magnolia grandiflora tree. This kind of tree has rather thick (kind of rubbery), large-sized leaves that can have an orange-tint coloration on their lower surface. Magnolia trees have large flowers that are typically white or pink (as shown here). 

Figure 7. Although flower buds of the tree shown here appeared in mid April, they did not “erupt” into open flowers for a several until late June before the flowers opened up and reveled the central core area (note: it was worth the many repeated trips to photograph these flowers, but it was worth it!).

Figure 8. Exterior view Magnolia grandiflora reproductive area of flower: total length 61 mm. Yellow part 16 mm wide and 30 mm long; lower part (consisting of reddish upper part and brownish lower areas), 31 mm length and 5 mm wide.

Figure 9. Cross-section of main (see yellow part of preceding figure) core area, with seeds in capsules. 

RERERENCES CITED: 

Alka. Floral designs by Alka. https://www.floraldesignsbyalka.com/blog/tag/Waterlilies.

Gomez, B. and four others. 2015. Montsechia, an ancient aquatic angiosperm. Proceeding of the National Academy of Sciences (PNSA). www.pnas.org/cgi/doi/10.1073/pnas. 150292411.