Aloe erinacea superficially resembles a  cactus, but closer examination reveals  that the plant consists of closely-spaced, spirally-arranged succulent leaves with spines along the edges. In cacti, leaves  are done away with altogether, or adapted as spines.  The picture at the right is a member of the genus Aloe. We all know the most common member of this genus, Aloe vera,  grown as a garden ornamental, as a source of skin ointment, or for its edible leaves. The species pictured, Aloe erinacea, with its compact, rounded overall shape and prominent spines ..read more

Blackberries grow on prickly vines or brambles,  and are members of the Rose Family (Rosaceae).  As I was picking mulberries from a tree in my back yard the other day, I was reminded of the similarity between blackberries and mulberries. They are strikingly similar in appearance.  Like most dark fruits, they are both rich in nutrients and protective phytochemicals. For the consumer, the primary differences are the somewhat milder, less sweet flavor, and the annoying little green stems of of mulberries. Depending on the climate, one or the other may be easier to gr ..read more

  Coconut palms commonly grow along tropical coastlines in a zone of salt-tolerant vegetation, but not directly in saltwater. Coconuts may fall onto the beach and be carried away by high tides, but not usually directly into the water.  Coconut palms have a distinctive, arching growth form, which is somewhat unusual among palms. Most solitary, tree-like palms grow straight upward rather rigidly. The reason for the coconut palm's graceful arch has led to much speculation online, some of it rather goofy, such as that they lean out over the shoreline ..read more

 As plant life evolved, several major breakthroughs allowed them to greatly expand their footprint across the globe. These breakthroughs were major macroevolutionary shifts brought about by a series of small microevolutionary adaptations. The essential characteristics of Plants are each associated with one or more of these major breakthroughs. Such events are described in more detail in Plant Life: a Brief History, I present here a brief synopsis of those major events: The earliest known fossil cyanobacteria formed layered colonies that slowly built pil ..read more

 A weed is sometimes defined as a plant out of place - or more often an overwhelming mass of plants popping up where we don't want them. It's a definition based on our futile attempts to to remake a landscape into something a human vision of tidiness. To be fair weeds are often exotic plants - invasive species from another continent freed from their usual constraints of competitors and predators. And so, weeds are also bad for our natural ecosystems, not just to our landscaping vanity. Weeds are mostly plants that are really good at spreading into disturbed habitats. They multiply rapid ..read more

Vining plants have an amazing ability to grab onto a  trellis, fence, or a twig on another plant by curling around it. It's an adaptation that allows the vine to grow rapidly upward using other objects for support. This gives them a distinct advantage over tree or shrub saplings that need to build their own woody support as they grow upwards. But how does it work?  The process is called thigmotropism, or touch-induced growth response.  Specialized organs called tendrils, or sometimes the stem of a young plant itself, can sense contact with a nearby object and al ..read more

In this Bearded Iris  the leaves are folded and flattened, forming a fan perpendicular to the tip of the rhizome. Many members of the Iris Family exhibit a peculiar, fan-shaped arrangement of their leaves. Leaves that are lined up on two sides of the stem in a single plane are called 2-ranked, or equitant.  Such an arrangement of leaves is not uncommon, occurring in the Traveler's Palm, Ravenala madagascariensis, for example. In the Traveler's Palm, leaves are equitant, but have conventional, spreading blades, with exposed upper and&nbs ..read more

The sepals of a rose bud are green and photosynthetic like fully developed leaves, and like the one on the left, sometimes even appear to partially subdivided like full leaves. From an evolutionary point-of-view, it is generally accepted that the parts of the flower originated as modified leaves. Though there is controversy about the nature of the earliest carpels and stamens, the leaf-like nature of petals and sepals is abundantly evident. Sepals are generally the most leaf-like, no doubt because they are the most recently evolved of the flower parts, and may have originated sep ..read more

One of my favorite plants is this cultivar of Anthurium andreanum, with spathes of pure, bright red. If treated well, it will bloom year-round. More correctly, the title of this post should read "why are the spathes of some species of Anthurium red?' - but that's way too wordy for a title.  The fact of the matter is that there are some 1000 species of the genus Anthurium, and only a few species have red spathes. The most commonly cultivated species is Anthurium andreanum, available in many different cultivars and hybrids. It is native to Ecuador and neighboring Columbia. Little is known abou ..read more

While the young leaves of Magnolia are developing, they are each wrapped in a white bract.Leaves are the most plastic of all plant organs.  That means that they can be modified in endless ways to result in a mind-boggling variety of shapes. Through evolution via adaptive modification, leaves form an endless array of light-gathering antennas, from the giant fronds of palms to the tiny scales of a juniper twig, but beyond that, have adapted into tendrils, insect-catching traps, and even the parts of the flower. In the fennel plant, the broad basal portions of the leaves, the leaf sheaths, overl ..read more