Examples of Mature Seed Pods and Seeds
This piece is a group product of Alamo Area Master Naturalists.
Unless specifically captioned otherwise, all photographs are by John Hill.
SEEDS ARE A SURVIVAL STRATEGY
As we wander through San Antonio’s parks and trails, we encounter highly diverse vegetation: shrubs, trees, vines, grasses, and plentiful wildflowers in various stages of growth and bloom. Many of our wildflowers are annuals or biennials, the plants only survive for one or two years. Some are perennials which regrow or continue to grow for many years. Many living plants have a common survival strategy which involves making seeds to survive poor growing seasons and conditions. The seeds scatter on hopefully fertile soil and germinate, growing into new plants when temperatures and rainfall are suitable. Can you think of plant reproduction strategies other than seeds? For example, plant nurseries produce many copies of some plants by asexual vegetative reproduction and ferns, mosses, hornworts, and liverworts reproduce by making spores. Note that Mushrooms are not considered plants, they are in a Kingdom of their own apart from plants and animals.
SEED PRODUCTION IS A PREDICTABLE SERIES OF EVENTS
a. First, a plant grows to a suitable size to reproduce; this means that it is vigorous enough to support flowering and seed production.
b. Then the plant grows sexual organs, flowers in the case of Angiosperms, which may contain either or both male and female reproductive parts. About 90% of flowering plant species are bisexual having both male and female parts. The process of reproduction occurs right within the individual flowers. These are sometimes referred to as “perfect flowers”; because they are self-sufficient in terms of reproductive capacity. The remaining 10% can be either monoecious or dioecious. Monoecious describes a single plant that bears separate male and female flowers on the same plant. Dioecious describes plants that have all male flowers on one plant and all female flowers on another plant. The following links provide multiple examples and photographs which contrast the differences between perfect and imperfect flowers, monoecious plants, and dioecious plants.
- What is the difference between perfect and imperfect flowers
- Examples of monoecious plants
- Examples of dioecious plants
c. As if monoecious and dioecious were not confusing enough, flowering plants are also classified by their seed structure and cellular organizations as Monocotyledons (Monocots) or Dicotyledons (Dicots). The names of these groups are derived from the number of cotyledons or seed leaves that the embryonic seedling has within its seed. A monocot will have only one cotyledon (seed leaf) and a dicot will have two cotyledons (seed leaves). Note that these seed leaves often look nothing like the true leaves that will form later. So be cautious when weeding newly sprouted plants.
d. There are several other distinguishing characteristics which can be seen in the links below. Note that this classification pertains only to flowering and hence seed producing plants. But it is not always obvious that a plant is a flowering plant. Oaks, maples, and sycamore are all dicot trees, but they do not produce obvious flowers. Grasses and cattails are monocots whose flowers are often overlooked because they do not have sepals or petals. For more detailed information about the parts of a seed, see the first link below. The second link gives history and more details distinguishing the monocot and dicot classes of flowering plants. The third link is a quick reference with photos on how to tell the difference between monocots and dicots.
e. All flowering plants require pollination. This is the process where male pollen is carried to receptive female parts of flowers by various means such as insects, bats, birds, or wind.
f. To get the results you want from growing a plant, it is important to know the reproductive strategy of the plant you are trying to grow. Dioecious plants require at least one plant of each gender to make fruit and seeds. Monecious plants with flowers of both sexes often require a second plant of a compatible species which blooms at the same time to complete pollination. This is because the differently sexed monoecious flowers may bloom at different times of the day or in different parts of the growing season to prevent self-fertilization. For landscaping purposes to prevent unwanted fruit, many people choose to grow only the male or only the female form of some plants. The Blanco Crabapple, Malus ioensis var. texana, is one example of a monecious fruit tree which only sets fruit when pollen from a compatible species is available. Possumhaw, Ilex decidua is an example of a dioecious fruit tree where you want to select a female to be able to have showy red berries. For an extensive list of pollination requirements of Hill Country native plants often available in San Antonio click here.
g. Upon successful pollination, the female parts of the flower grow seed pods to contain the developing seeds. Seed pods edible by humans are called fruit.
h. Once the seeds have adequately developed inside the pods and acquired protective coatings to survive harsh conditions, the pods ripen or the fruit falls and the seeds are broadcast to wait for proper conditions to start a new growth cycle.
COLLECTING AND GROWING SEED FROM NATIVE PLANTS
This can be a great experience and sometimes the only way to acquire specimens of plants not commonly supplied by nurseries.
a. Since all wildflowers produce seeds, if we find seed pods when they are ripe and before the seeds are dispersed, we can collect seeds and grow plants from them. The best time to plant such seeds is to mimic the plant’s distribution cycle and scatter the seed when it is ripe for dispersal. If you are in the area where the plant is native, this avoids special requirements for seed stratification, or artificial periods of cold or damp. If you are like most people, this means that you need to carefully label seed packets, germinating containers, and planting areas as to what you have collected or planted and when; because, a long time can pass between seed sowing and growth. It is probably not a good idea to mix too many seeds into the same container. When in doubt, let a plant grow until you are sure what it is.
b. The only real way to tell if seed is ripe for collection is to visit the plant regularly and observe the development of the seed pod or fruit. For example, look at Mustang Grape vines to see if the fruit is ripe for eating. If so, it is ripe for planting. If a seed pod is splitting, the seed is probably ripe. There is almost always a window of time to determine the comparative ripeness of seed pods or fruits to obtain a few seeds that have not yet been naturally distributed.
c. Seed collection should follow the guidelines below which are paraphrased from the International Carnivorous Plant Society, ICPS. For anyone interested in carnivorous plants, members of the ICPS have access to the ICPS Seed Bank where you can obtain seeds of carnivorous plants, some native to Texas. You can obtain more information or join the ICPS here.
- Collect on private property only with the approval of the property owner.
- Follow all local, national, and international laws when collecting seed. Many areas have special protection status and prohibit collecting seeds without collection permits. It is the collector’s responsibility to be sure all laws are being observed.
- Do NOT collect every seed available from existing plants. Do leave enough seed for the plant(s) to adequately restore its part of the wild seed bank.
- Seeds are best collected in paper bags or paper envelopes. Plastic bags can condense unwanted moisture.
- Keep collected seeds away from intense heat (as on a car dashboard). High temperatures will kill seeds.
- Collect only mature seeds to increase chances of germination.
- Separate seeds of different plants into different packets.
- Label collected seeds as soon as possible with the plant name, date of collection, and general location where collected. This information can be easily forgotten.
FORBS, VINES, SHRUBS, AND TREES ALL CAN PROVIDE SEEDS FOR GERMINATION
For a general tutorial on growing natives from seed, check out How to Grow Native Seed.
Here are some examples of native plants common to our area that can provide seeds for your collection. These were selected because they are easy to recognize. Most of us have our favorite plants and this is only a list of some of our favorites. There is a short description together with links where you can get more information about each plant. Note that the scientific names of these plants are shown in italics and follow the Plants of the World On-Line (POWO) naming conventions as used by iNaturalist. For more information about names used by iNaturalist, here.
a. Forbs: Prickly Poppy (Argemone albiflora), and Cowpen Daisy (Verbesina encelioides). A larger but not exhaustive list of Forbs is available here. Or visit the Lady Bird Johnson Wildflower Plant Database.
b. Vines: Alamo Vine (Distimake dissectus), and Snapdragon Vine (Maurandya antirrhiniflora).
c. Shrubs: Turk’s Cap (Malvaviscus arboreus), and Rock Rose (Pavonia lasiopetala). A larger list of shrubs is available here.
d. Trees: Mexican Buckeye (Ungnadia speciosa), and Texas Mountain Laurel (Dermatophyllum secundiflorum)
Prickly Poppy (Argemone albiflora) can be seen blooming in both sunny areas and shade from March through May. Its lovely pale white flowers seem to open during the day and close at night. After successful pollination, the flower petals fall off and a very prickly seed pod develops at the base of the old flower. In the spring of 2019, if you walk along paths near the Leon Valley Vista trailhead you can check out the Prickly Poppy plants to determine if their seeds were ripe for picking. The flower petals fall, then the pods developed. Seed pods ripened just enough for harvest about July 4th. Select a few plants and cut some seed pods into a paper sack. Seeds escaping the pods and rattling about in the bag told me they were ready. Photos and more info on Prickly Poppy are available here, and here.
Cowpen Daisy (Verbesina encelioides): Like many members of the sunflower family, Cowpen Daisy germinates easily from seed. Also called Butter Daisy or Golden Crownbeard, Cowpen Daisy is sometimes included in native seed mixes, but it is almost impossible to find the seeds for sale on their own. Cowpen Daisy forms prolific seed heads after flowering. Each head contains about 75 seeds. They dry out in early winter and if not consumed by wildlife, drop to the ground and rest for a while. In early spring, they sprout a green carpet that’s easy to thin. George Cates, chief seed wrangler at Native American Seed, offers this advice: “Throw the seed on disturbed ground, walk away.”
Alamo Vine (Distimake dissectus) grows wild along the Leon Valley trail and in San Antonio parks. It is a relative of morning glory and grows well in shaded areas. We believe that it blooms mid-mornings from late spring until early fall, with flowers, seed pods, and seeds all available at the same time. The ripened seed pods resemble a wooden flower, which explains one of its common names: Woodrose. It is often used in floral arrangements. Its seeds can be collected whenever the dried pods appear, with four (poisonous to humans) seeds per pod formed in the rounded part of the pod. This vine can be aggressive. Check here for more information on Alamo Vines, here.
Snapdragon Vine (Maurandella antirrhiniflora also known as Asarina antirrhiniflora) grows wild on the Leon Creek Greenway, Phil Hardberger Park, and all over the county. The extensively twining stems bear thumbnail-sized, arrowhead-shaped, medium green leaves accented by numerous scattered periwinkle blue baby snapdragon-like flowers highlighted by a yellow throat. Ornamentally, snapdragon vine is an up-close vine, hardly showy from a distance, its fragile beauty is best appreciated near an entry or garden bench, clambering up a small trellis or dangling over a limestone boulder. Although it is not winter hardy in much of Texas, it grows so quickly from seed in full sun or part shade, that it may be used as an annual in a wide range of soils, given good drainage. Rain or irrigation will promote faster growth and extend its blooming season. It is not unusual for snapdragon vine to re-seed itself for the following year. Reference information here.
Turk’s Cap (Malvaviscus drummondii) has flowers and fruit edible by humans and grows in all sorts of shaded and partially protected areas in the parks and along trails. After its red flowers are pollinated, it develops small red fruits that contain seeds of the Turk’s Cap. Flowers and seed pods often coexist on the same plant. Supposedly their taste is reminiscent of cucumbers. It is a great understory shrub.
Rock Rose (Pavonia lasiopetala) is a popular garden accent plant throughout Texas, even though it originates on dry, rocky woods or banks of South, Central or West Texas. Its popularity is no doubt due to its long bloom period and versatility, accepting full sun to half day shade, a variety of soils, and very dry to regularly irrigated conditions. This small, perennial shrub is woody at the base, herbaceous above, bearing light green, velvety, heart-shaped leaves and deep rose-pink miniature hibiscus-like flowers which open in the morning and close by early afternoon in our highest heat. Its naturally loose, open-branching form may be kept more compact by frequent pruning, which promotes new growth and more flowers. Pavonia is reputed to be short-lived: three to six years, but self sows readily. It is so easily propagated by softwood cuttings that it may be easier to grow from cuttings than from seed. Just wrap a damp cloth or paper towel around the cut portion of a stem to keep it moist until it is ready for rooting. If available, dust a little root hormone on the cut end. Then place into potting soil and keep regularly watered.
Mexican Buckeye (Ungnadia speciosa) is not a true buckeye as a second common name “False Buckeye” indicates. It is a very early spring-flowering small tree or tall shrub in the soapberry family. Like Western Soapberry it has a compound leaf, but its three-lobed seedpod, containing three large dark brown to reddish seeds which rattle (when shaken after ripening) is like the large seedpods of some trees or shrubs in the Buckeye family. That might be the reason for its common name. The true value of the Mexican Buckeye is its drought tolerance and its ornamental appearance. Its fragrant pink to light purple blooms appear very early in the spring and can rival, on a healthy tree, the blooms of the Redbud tree, another early bloomer.
Texas Mountain Laurel
Texas Mountain Laurel (Dermatophyllum secundiflorum also known as Sophora secundiflora): This is one of the early blooming small trees of Texas and is often used as a landscape showpiece. Its blooms are primarily purple-blue; as a tree near the entrance to Government Canyon State Natural Area shows it may have white blooms. The blooms supposedly smell like grape Kool Aid. It can bloom as early as late February, about the same time as Agarita. After the Mountain Laurel blooms, strings of developing seeds grow. When the seeds ripen, they turn bright red or orange and fall under the mother plant. Children who know about these seeds often call them “burn beans” because you can rub them on cement and they get hot enough to feel like you are being burned if they are pressed against sensitive skin. Although the seed coat is quite hard, the seeds are relatively easy to germinate when simply pressed into the ground and watered regularly. For more information about Texas Mountain Laurel visit this site.
OTHER NATIVE PLANTS
All native plants have a place in the local ecosystem. Sometimes their utility to humans is not immediately obvious. Changing landscaping desires, agricultural needs, or agricultural methods may have turned formerly useful plants into “weed plants” or “weeds”. Just remember, what is a weed to humans may be wonderful food or housing to wild birds, animals, or insects.
Finally, if you click on The Table of Contents button, it will take you to our index of Talking Points where you can find articles on Ashe Juniper, Wildflowers, Texas Kidneywood, Prickly Pear, Texas Persimmon, Agarita, and Grasses.
For more information for children see, Seeds We Need.