Tag Archives: dicot

Bluebonnets in the fall.

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Walking at dawn in the fall in Texas the yellows and golds and reds of the grasses and leaves tend to dominate.

Fall sunrise in Texas

But look closer, below the red and yellow grasses, and there are round, bright green seed leaves of Lupinus texensis– the Texas bluebonnet. After the heat of summer and the fall rains, around September or October, these emerald gems appear close to the ground. Soon afterwards, especially if there is more rain, the palmate leaves with their pointed hairy leaflets appear. On a morning with heavy dew the moisture collects on these leaves so that they shimmer like silver in the first rays of light, collecting little pearls of moisture at the base of the leaflets.

Dew decked bluebonnets in fall.

As the seedlings of these annuals grow they send down roots that have nodules. As members of the family Fabaceae they form symbiotic relationships with bacteria that fix gaseous nitrogen for the plant. This nitrogen gets passed on into the soil enriching it for other plants. In return the bacteria get carbohydrates from the plant.

Through winter storms these small green leafy rosettes wait for spring and the chance to flower. With good fall and spring rains fields of them will appear around March and April. The spike inflorescences of multiple blue flowers are easily identified as belonging to the pea family with the banner, wing and keel forming each flower.

Field of bluebonnets in Texas spring

Annual Pennyroyal

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Hedeoma acinoides has appeared in abundance after the inch of rain this past weekend.  

Blooming for a short time in the spring it is a delightful miniature spring annual.  Only an inch or three high, in these pictures, it has created delightful little patches that look like miniature forests.

Plant identification books such as Marshall Enquist’s Wildflowers of Texas say it can be up to 8 inches.  Common in the rocky limestones of the hill country this member of the Lamiaceae or mint family has a minty smell if you crush the leaves a little.

This is not the only member of the family Lamiaceae to be called Pennyroyal, several other genera have this common name. In Culpeppers Herbal the pennyroyal he refers to grows in damp areas and flowers at the end of August.

Breaking the winter fast

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Blanco crab apple at Selah Bamberger Ranch

It’s been a curiously cold winter here in Texas, while elsewhere in the country has been inundated by unrelenting snow storms.  Still the first Spring trees are beginning to flower and the crab apples have been blooming for almost three weeks despite the weather alternating between freezing temperatures as low as 28F and highs near the 80’s.  Here the Blanco crabapple (Malus ioensis var. texana), an endemic species of the Texas Hill Country, is blooming next to a tributary of Miller Creek on the Bamberger ranch.  This splendid tree is a member of the Rosaceae family and, as it’s genus (Malus) suggests related to the domesticated apple.  The characters that place this plant in the Rosaceae family are best seen in its flowers.  The blooms are actinomorphic, meaning they are radially symmetrical.  They have five petals, as can be seen in the adjacent close up, and five sepals.  The flowers have both male and female parts, making them hermaphroditic, and many stamens arranged in whorls.  Three stigma and styles (slightly greenish structures at the center of the flower) are evident in this photograph

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Close up of the Crab apple flower by Abe Halbreich

disappearing into the top of the ovary that will ultimately become the apple once the flowers have been pollinated.  The base of the flower, calyx (sepals), corolla (petals) and androecium (filaments of the stamens) essentially fuse to form a hypanthium enclosing the ovary.  According to the Ladybird Johnson site, this species is particularly important to a variety of native bees.  Naturally the bitter fruit that appear later in the summer are food for a variety of animals.  As a harbinger of spring and warmer weather it brightens the dry, cold landscape and it’s bright fresh blooms easily draw the eye against the brown palette of the grasses and olive green cedars.

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Lake Madrone at the Bamberger Ranch in February 2014

Texas Mountain Laurel – Sophora secundiflora

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OLYMPUS DIGITAL CAMERASpring is springing up quickly after our warmish winter.  The mountain laurels have been blooming for over a month now and are slowly beginning to fade.  Their bumpy seed pods, containing poisonous seeds, are appearing from the delicate purple-blue blooms that still fill the night with heady scent.  I thought it might be fun to take a closer look at these flowers since this species is a member of the Fabaceae, one of the largest and most cosmopolitan of all plant groups. Just about anywhere in the world you will find examples of the pea family.  They could be evergreen, deciduous, climbers, herbaceous plants or trees.  Specifically, Texas Mountain Laurel is a beautiful evergreen multi-trunked trees that is part of the sub-family Faboideae.  This is the group of Fabaceae that we typically recognize as “pea”. OLYMPUS DIGITAL CAMERA The other two subfamilies are Mimosoidae and Caesalpiniodae.

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Half flower diagram of Texas Mountain Laurel

So what is a “classic” pea flower. It has a floral structure where the petals are arranged into banner, wings and keel.

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Stigma, style and ovary of the Texas mountain laurel

The banner is one large petal with two wing petals enclosing two keel petals.  The keel closes around the 10 stamens  and the ovary that will later develop into the pod if the flower is pollinated.  Two curious features of the flower are the widening of the filaments at the base (filaments support the anther forming the stamen) and a protrusion on the lower side of the keel petal which seem to help the petals stay closed over the stamens and stigma.

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10 stamens clustered tightly around the gynoecium

What’s green in January? #1

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Thibam2s past Sunday I took a drive out into the hill country. I was visiting one of my favorite places – the Bamberger Ranch.  While there are green trees (Live oaks – Quercus fusiformis and cedars – Juniperus asheii) scattered through the landscape there were many without any leaves.  bam1Yet they still had what appeared to be balls of greenness high up in their canopy.OLYMPUS DIGITAL CAMERA  These apparently innocuous tufts of green are actually parasites (mistletoe –Phoradenron tomentosum) with their haustoria deep in the xylem and phloem of the plant they draw out the nutrients from the very heart of each branchOLYMPUS DIGITAL CAMERA.  The leafy parts seen here are growing out of a small Spanish Oak (Quercus texana).  The texture of the leaves is leathery and quite tough.  What is not seen here are the tiny white berries that the birds love to eat.  We are perhaps more familiar with the idea of red berries on mistletoe since that is what is found on the european mistletoe Viscum album.  When the berries pass through the gut of the bird they become goeey and the bird has to wipe its bottom on a branch to remove the dropping.  In this way the berry becomes attached to the next victim, commonly Cedar elms (Ulmus crassifolia) or hackberry (Celtis laevigata), and the haustoria (specially adapted roots) can grow into the bark and a new plant is infected.  Amazingly haustoria can extend deep into the plant.  After removing an infected branch from a Spanish oak I traced haustoria up to 2 yards inside the vessels of the plant! OLYMPUS DIGITAL CAMERA I do wonder if trees are more prone to infection with all the droughts we have been having.  I seem to be noticing it more and more each winter and infected trees seem to have more infestations.  Do plants typically have resistance to parasites and that is weakend by drought?

Fall Color

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cedar elm (Ulmus crassifolia)

cedar elm (Ulmus crassifolia)

While many parts of the country have begun their winter, here in Texas we are still enjoying the balmy days of Autumn.  While our fall color isn’t perhaps as dramatic as some places in the country we still have some lovely yellows and reds set against the backdrop of the evergreen cedar. (Juniperus ashei).  Cedar elms are tall stately trees that can be found on their own or hidden within the forest.  This year their small winged fruits covered the ground in September and October as their yellow golden leaves are doing now.

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Bur oak (Quercus macrocarpa)

Another source for hints of gold on the hillside is the Bur Oak.  The leaves of this oak are enormous as are their beautiful acorns that have caps with dramatic “burrs” surrounding them.  A beautiful tree in a park setting this wonderful tree is now dropping its leaves, that are the size of a childs shoe, making a crunchy brown flooring for park goers to enjoy in the fall light.

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Spanish Oak (Quercus buckleyi or texana)

Oaks are also a source of dramatic reds seen along roads and on hillsides. The Spanish Oak belongs to the group of Oaks known as the Red Oaks and doesn’t disappoint. The identification of this fast growing species can be tricky as it has much in common with the Shumard Oak (Quercus shumardii) and Southern Red Oak (Quercus falcata). Another source of deep red is from a slightly small tree, the flame leaf sumac (Rhus lanceolata). This wonderful plant specimen changes from a vibrant green in the spring to a deep red in the fall. It candelabra like inflorescences of tiny cream flowers resulting in reddish seeds which marks the beginning of the change in late September/October. Their color emphasized by the late fall light they optimize winter metaphor of burning the old and opening ways for new beginnings.

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The diversity of the ‘star’ flowers – Asteraceae

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Black foot daisy (Melapodium leucanthum) – Tribe Heliantheae

Firewheel (Gaillardia pulchella) – Tribe Helenieae

A humble daisy is the characteristic member of this cosmopolitan group.  You can imagine that a plant family with members spread across the globe might well have species occupying a range of niches.  The vast diversity is taxonomically captured by dividing the family up into sub families and tribes.

The tribes that you might be the most familiar with are the Heliantheae and Helenieae (the classic daisy form), the Cynareae (artichokes and thistles)

Texas thistle (Cirsium texanum)

, Astereae (which has Golden rod and the fleabanes as members)

Prairie fleabane (Erigeron modestus) – Tribe Asteraeae

and the ubiquitous Chicorieae (dandelions and chicory).

Colorado dandelion

While most asters (or composites) are herbaceous perennial, biennials or annuals there are also shrubs and vines.  The complexity of this group extends to its taxonomy and you may see frequent name changes.  In fact you might see the family referred to as Compositae!  This name is in reference to the classic head inflorescence of the family.The flowers (disc florets) are typically collected together and surrounded by what are termed ray florets.  You might be tempted to call them petals but they are in fact a different type of flower to the others on the head.  In the image to the left you can see (from outside to center)the large yellow ray florets, the  yellow stigmas (female parts) of individual flowers and the brown anthers (male parts) in the center disc florets.

The curiously square bracts of Nerve- ray (Tetragonotheca texana – Tribe Heliantheae)

Below the inflorescence are bracts that you might mistake for sepals (if you viewed the whole daisy as a flower).  The bracts of different species are quite different and might even be sticky or spiky!

Brownish bracts of Navajo tea ( Thelesperma simplicifolium – Tribe Heliantheae)

Helianthus maximiliani

Ratibida columnaris

Here we have a classic example in the case of the sunflower – Maximilian sunflower to be exact (Helianthus maximiliani – Tribe Heliantheae).  A variation on this capitulum inflorescence is Ratibida columnifera (also in tribe Heliantheae) where the platform of tiny flowers are proud of the bronze or yellow ray florets.

The multiple inflorescences of Poverty weed

Of course Nature never obeys our taxonomic rules so there are other members of the family that do not have the classic daisy flower.  Poverty weed (Baccharis neglecta – Tribe Astereae), for instance, does not conform to the usual idea of a “daisy”.  A tall shrub, it grows well in disturbed areas and is very difficult to remove!  In fall it becomes very attractive covered with multiple inflorescences.  It’s overall silvery appearance earns it a place in the landscape.  Come spring I will be wondering how to get rid of it again!

Blue mist flower (Eupatorium coelestinum – Tribe Eupatorieae)

You can see that the inflorescence of poverty weed lacks the ray florets common in other tribes.

They are also much reduced or absent in the Eupatorieae.  Blue mist flower (seen here with friend) (Eupatorium coelestinum) is a beautiful summer flowering example of this tribe.  There is a wealth of hardy Asteraceae species that can be utilized for different effects in the landscape.  They are a global family well worth exploring.

Hidden Jewels

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The delicacy of Texas plants frequently surprises me.  One of my personal favorites that I look for each spring is the Pearl milkweed vine, or netted milkweed vine (Matelea reticulata) that is endemic to Texas.

Seen here with the White leaf leather flower (Clematis glaucophylla), this small green flower with brown-red speckles has a center that is pearl colored.  What is even more surprising is the comparitively enormous pod that appears.  This type of seed pod is not uncommon in the family that this vine belongs to -Asclepidaceae.

This vine that twines 15-20 ft up trees and over shrubs is not very obvious until the eye-catching spots of silver appear.  It is interesting to imagine it as one of several over an arch or along a fence.  Where could you imagine using it?