Download A Natural History of Texas Milkweed

presented by
Craig Hensley, Park Interpreter/Naturalist
Guadalupe River State Park
 Formerly in the family Asclepiadaceae, now
a subfamily (Asclepiadoideae) in the family
Apocynaceae
 Approximately 2,900 species of milkweeds
 Approximately 135 species in North America
 Named after the Greek god of healing
Asklepios
 Represented in the night sky as Ophiuchus
 Origin of the name milkweed is of course…
By the way,
Snow-on-theMountain, while
having milky sap,
is not a milkweed

 Cardiac Glycosides = Heart-stopping
 Native Americans and others have used milkweeds for
many kinds of ailments and even as foods including:
Snakebite
Warts
Rheumatism
Contraceptive
Chewing Gum
Pleurisy
Potherbs
Fritters
Syphilis
Ringworm
Asthma
Use of Pods and Silk*
Larger pods were used as
utensils by some Native
Americans
Children used them as
doll cradles and fairy boats
Fibers were once spun for
use as candle wicking – said
to burn better and smell
less
Milkweed fluff was used
to stuff life jackets during
WWII
*Information from Elizabeth Silverthorne’s “Legends & Lore of Texas Wildflowers & “Lone Star Wildflowers
by Lashara J. Nieland & Willa F. Finley
 Represented by a total of 62 species statewide
 The most common and widely recognized genus of
milkweed is Asclepias, with 37 recognized species, of
which 36 are native to Texas, Tropical Milkweed being the
lone non-native*
 Other genera, representing vining plants include:
 Matelea – 15 species
 Funestrum – 4 species
 Cynanchum – 5 species
 Periploca – 1 species (introduced -- Silkvine)
*While there are those that will disagree, Woodson in in the 1954 Annals of the
Missouri Botanical Garden wrote that the origin, while “conjectural” , “is Antilles,
Mexico and Central America, or even southern South America…”
Of those, five species have very limited ranges;
Nine species are found only in the Big Bend
region of TX;
Five species are restricted primarily to the
Panhandle
In the Hill Country, a total of 21 species may be
found
Flowering periods are generally expanded,
partly due to nature of species and partly due to
land management – respond to mowing and
burning
CA – Calyx = Sepals =5
C – Corolla = Petals = 5
HD – Hood + HN – Horn + A – Anther = Stamens
S – Stigma + O – Ovary = Pistil
Pollinia
Spectacular milkweed of
prairie region
Bright orange to red
flowers borne at end of
stems
Multi-stemmed plants
with narrow leaves covered
with coarse hairs
Lacks the milky sap
common to milkweeds
Blooms April-September
Beautiful pink flowers
borne on 2-5 foot plants
Distribution in Texas is
limited
Wetland plant that likes
wet, clay-based soils
Wonderful plant to attract
butterflies
Blooms August-October
Wetland plant that likes wet,
clay-based soils
Flowers pinkish with tall, narrow
hoods; very fragrant
Blooms June-August
Branching, narrow-leaved
species with small clusters of
reddish purple flowers
Flowers few to a cluster with
multiple clusters present
Petals reflexed
Blooms May-September
A species with limited
distribution in Texas
Grows in open woodlands
Pink flowers in large clusters
borne in leaf axils
Blooms May-June
Photo by Emily Weiner
Diminutive plant of
Big Bend region
Leaves few,
tomentose, roundish
Pale pink-purple
petals reflexed
Blooms AprilAugust
Tall milkweed with numerous,
large leaves
Flowers borne in clusters ,
somewhat obscured by the leaves
Cream-colored flowers with upturned petals and large, globose
hoods
Blooms May-August
Attractive species that would make
a wonderful garden plant
Upwards of two feet with elliptical
leaves
Flowers borne at top of branches in
umbel-like clusters
White petals reflexed and spreading
Blooms May-July
 Milkweed of wetland
edges and bottomland
woodlands in eastern
part of Texas
 White flower clusters
arise above ovate leaves
 Has become
increasingly rare in
Texas
 Blooms April-October
Photo from www.illinoiswildflowers.info
 Beautiful milkweed of pine-oak
woodlands and Pineywoods
 Opposite ovate leaves
 White flowers with red ring at
base of hoods
 Blooms May-June
Uncommon in the Hill
Country but widely
distributed in US
Two feet or less tall
with whorled, thread-like
leaves
Multiple, small flower
clusters arising from base
of leaves
Blooms May-November
 Slender-leaved plant of
southeast Texas to edge of Hill
Country
 Paired, narrow leaves
 Solitary flower clusters borne
at base of paired leaves
 Blooms April-October
 Narrow-leaved milkweed
of the Panhandle
 Leaves crowded from base
upward
 Flower clusters near to top
of plant; greenish to
reddish in color
 Blooms July-August
Photo from www.kswildflower.org
 Widespread, narrow-
Photo from swbiodiversity.org
leaved perennial
 Leaves alternate to
opposite and scattered
along stem
 Flower clusters near to top
of plant; greenish to
reddish in color
 Blooms May-September
Upright species to 3 feet
Found scattered in open areas
and along woodland edges
Multiple flower heads, each borne
in axils of upper leaves
Green flowers, petals strongly
reflexed
Stems appear in zig-zag pattern
Low-growing perennial to
two feet tall , spreading
Found along roadsides ,
open areas, disturbed
ground
Flowers from March
through December
Favorite of a host of
butterflies and bees
Propagation: Cold, moist
stratification at 40 degrees
for three months; can be
sown directly in fall
Found in open, often dry
locations, one of most
common milkweeds
At first glance similar in
appearance to Antelope Horn
Leaves wavy-margined and
sometimes notched at tip
Typically only one flower
head per plant
Flower petals upright
Widespread in eastern half
of TX
Wide-ranging, more common in
west Texas
Somewhat inconspicuous
milkweed of dry, even sandy soils
Grows to 1.5 feet tall with
ovate, pubescent leaves
Flower clusters borne in leaf
axils
Green petals reflexed
Noticeably stalked horns
Blooms from March to October
Tropical Milkweed – Curse or What?
Milkweed Vines
One of several vining
species of milkweeds
Chordate-shaped leaves
Flowers from April through
October
Petals are reticulated and
stamens are capped with
silver top
Pods have sharp points on
outer surface
Uncommon endemic to the
Edwards Plateau
Pointed, heart-shaped
leaves
Flowers lack the silver top
Petals are reticulate only at
the tips, more or less parallelveined toward base
Flowers in April and May
Matelea edwardsensis
Plateau Milkvine
Matelea biflora
Purple Milkweed Vine
Scattered in grassland areas,
but often unnoticed as it is
typically prostrate
Opposite heart-shaped
leaves
Flowers purple, few to a
cluster
Pods with spikes
Flowers in April to June
Herbaceous vining species
Arrow-shaped, narrow with
wavy/tooth-like margins
Flowers in small purple clusters
Flowers from April to June
Perennial climbing or
trailing vine
Prefers sandy soils;
scattered throughout
state
Clusters of flowers have
purple-tinged upturned
petals
Blooms from May to
September
Herbaceous vining species
Pointed, heart-shaped
leaves
Flowers small and green
Flowers in June
Herbaceous vining species
Pointed, narrowly oval
leaves
Flowers small and white
in few-flowered clusters
Flowers from May to
August
Monarch
Queen
Large Milkweed Bug
Immature
Small Milkweed Bug
Variegated Fritillary
Question Mark
Gray Hairstreak
Olive (Juniper) Hairstreak
Tawny-edged Skipper
Dun Skipper
Southern Cloudywing
Yellow-bellied
Bee Assassin
Bug
Crab Spider
Ladybird
Beetle
Historic Issues:
 Cutting of oyamel fir forests in the Monarch
Butterfly Biosphere Reserve
 North American loss of habitat due to
agriculture and development
 Severe weather events at overwintering sites
Current Issues (including those above):
 GMO crops and widespread application of Round-up
throughout midwest
 Decrease of Conservation Reserve Program lands
 Neonictinoid use by growers of commercial garden
plants
 Climate Change
On-going Efforts:
 Project Milkweed – sponsored by The Xerces Society
(in cooperation with Monarch Joint Venture & USDA
Natural Resources Conservation Service grant)
 Attempting to promote the planting of regionally
appropriate native milkweeds through education,
awareness and guidelines
 Monarch Watch – is currently working with growers
to fine tune the germination and growing of a variety
of milkweed plants – zizotes, green milkweed and
antelope horns for Texas
 Monarch Waystations – over 10,000 of these now
 Monarch Larva Monitoring Project (Univ. of MN)
– 800 sites nationwide – GRSP is one of three state
parks with active sites
https://tpwd.texas.gov/huntwild/wild/wildlife_diversity/texas_nature_trackers/monarch/
 Keep in mind that as surely as monarchs need
milkweeds for egg-laying and rearing their young in the
spring as they migrate into the state, monarchs need
fall-blooming wildflowers like cowpen daisy, blazing
star, Maximilian’s sunflower and frostweed as they
move south to their wintering grounds.
 Observers of milkweed can contribute to the knowledge
of these important plants not only as host plants to
monarchs, but also to their values to other pollinators.
 Master Naturalist chapters statewide can contribute to
a better understanding of which milkweeds are used by
monarchs as larval food sources on a local and regional
basis, as well as reporting milkweed observations
through iNaturalist.
Monarch Joint Venture
Oberhauser, K.S., Nail K. R., & Altizer, S. 2015 Monarchs in a
Changing World.
Oberhauser, K.S. & Solensky, M.J. 2004. The Monarch
Butterfly: Biology and Conservation
Singhurst, J., Hutchins, B. and Holmes, W.C. 2015.
Identification of Milkweeds (Asclepias, Family
Apocynaceae) in Texas. Texas Parks and Wildlife
Department PWD RP W7000-1803 (06/15).
Woodson, R.E. 1954. The North American species of
Asclepias (L.). Ann. Missouri Bot. Gard. 41(1): 1-171.
USDA, NRCS. 2015. The PLANTS Database, July 2015).
National Plant Data Team, Greensboro, NC 274014901 USA.
“To keep every cog and wheel is the first
precaution of intelligent thinking.”
-Aldo Leopold