Know Your Natives – Rattle Weed

Rattle weed (Astragalus canadensis) of the Pea (Fabaceae) family, occurs throughout the US except for Arizona, Florida and the far Northeast.  It is also found throughout Canada.  In Arkansas, rattle weed occurs in scattered counties across the state, with most occurrences in the Interior Highlands of the northwestern half of the state.  Also known as Canadian milk vetch, rattle weed is an herbaceous perennial.  It is found in sunny and wet to somewhat dry prairies, open woodlands, roadsides, thickets and stream banks.

The plant has shallow, widely branched near-surface roots.  Spring growth sprouts at numerous points along the roots.  Early leaves develop from erect, light green stems that eventually grow to 1½ – 4 feet tall.  Plants in strong sun may develop reddish stems.  The plant’s long slender stems, which have similar girth from ground to inflorescence, may recline later in the growing season.  The stems are hollow and somewhat square in cross-section, with minor ridging all around.  Secondary stems arise from leaf axils, and leaf scars occur all around the stems.  The stems may be smooth or pubescent.

Rattle weed - Astragalus canadensisPhoto 1:  New stems of rattle weed emerge in early spring from various points along branched roots.  With age, colonies may form.

Medium-green, odd-pinnate compound leaves may be a foot long with up to about 31 widely spaced leaflets.  Opposite (mostly) leaflets decrease in size towards leaf tips.  Insignificant stipules are triangular and pointed.  The rachis is grooved along its upper length.  The smoothed-edged, oblong to elliptic leaflets on short petiolules are up to about 1½ inches long and ¾ inch wide, with rounded bases and rounded to emarginate tips.  Leaflets are generally smooth or slightly hairy on upper surfaces, with stiff short hairs on lower surfaces.

Rattle weed - Astragalus canadensisPhoto 2:  Ten-inch mid-stem leaves of rattle weed in late spring.  Leaflets are normally opposite, but may occasionally be alternate (see upper leaf).

The inflorescence of rattle weed, occurring in late spring, consists of multiple upright racemes of densely clustered white to pale greenish-yellow, pea-shaped flowers which grow from axils of upper leaves along primary and secondary stems.  Racemes, on long stems (peduncles), have an elongated cone shape with 50 to 120 or more flowers whorled evenly all around the upper two-thirds of the stem.  Each flower bud is subtended by a bract which withers as the flower opens.  Raceme and stem combined are up to 7 inches long.

Rattle weed - Astragalus canadensisPhoto 3:  Raceme with flower buds inclined upward.  Each bud is subtended by a bract.

Flowers of rattle weed open in succession from the bases of the racemes to tops.  Open flowers toward the bottom of the racemes tilt downward while higher flowers are horizontal and then tilted upward.   Flowers, ½ to ¾ inch long with a greenish-white, hairy calyx with five triangular pointed lobes, have a tubular corolla composed of five creamy greenish-white petals.  The flowers are pea-like and elongated with a petal forming the upper banner, two lateral petals and with two petals forming the keel.  The stamens, pistil and style are enclosed by the keel.

Rattle weed - Astragalus canadensisPhoto 4:  Rattle weed racemes grow from multiple leaf axils near tops of long, slender stems.

Flowers are replaced by inflated, smooth and oval green pods with long pointed tips.  The pods, about ½ to ¾ inch long, become dark brown and woody in texture with maturity.  The dozen or so seeds in a dry pod become loose and rattle when stems are shaken, thus the common name “rattle weed.”  The pods are persistent.

Rattle weed - Astragalus canadensisPhoto 5:  Maturing seed pods.  All flowers do not produce seed.

Rattle weed, as a fairly tall specimen plant, can be a good garden plant.  Its compound leaves add textural variety and multiple attractive flower clusters are born at the top of the plant.  It is not known to be aggressive either from seed or root.  The nectar is used by various butterflies and other insects.  Seeds are eaten by song birds and turkey.  The foliage may be eaten by deer and other herbivores.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Jack-in-the-Pulpit & Green-Dragon

Jack-in-the-pulpit and green-dragon, in the Arum (Araceae) Family, are herbaceous perennial monocots that occur throughout the state in similar habitats.  Both are smooth overall and hairless.  Plants range from 2 inches to 2 feet in height.  Habitats include mesic (well-balanced moisture) deciduous woodlands and thickets and hillside seeps with light shade and humus-rich soil.  Both are dioecious; that is, the flowers are unisexual, staminate or pistillate, such that two plants are required for cross-pollination and fertilization. In general a plant will be staminate for several years, contributing only pollen to the reproductive process, until enough energy has accrued in the corm to produce seeds and fruits. The sex change may be brought about by age or health of the plant.  Corms, about an inch below the surface, may grow to 1½ inches across with a few fibrous roots.  Both species produce an elongated cluster (corn-cob-like) of bright shiny red berries that appear identical for both plants (photo 1).  One- or two-year-old plants of both species have a single leaf with three leaflets and appear identical.  Both species produce clonal plantlets, and thick-standing colonies of varying sized plants can develop.  Leaves and flowers unfurl initially from a pointed sheaf arising from each corm.  Inflorescences, on top of stout fleshy upright stalks, emerge at the same time as leaves.

Green Dragon - Arisaema dracontiumPhoto 1:  Mature cluster of green-dragon berries.  Cluster on Jack-in-the pulpit would appear identical.

Berries (¼ inch across) enclosing one to several seeds, at first green, become bright red as female plants begin to wither in late summer and fall.  Berries remain attached to the dry spadix, resulting in an ovoid mass of showy berries up to 2 inches long which stay on the stem even when stem has dried.  A cluster can consist of up to 150 berries, each with 1 to 3 rounded flat-sided light tan seeds.

Either plant is an excellent woodland garden plant, being easy to cultivate and requiring little care.  Along with the interesting characteristics of the vegetation, the cluster of berries in late summer and fall is attractive.  Birds and mammals eat the berries, but berries of both plants should be considered poisonous to people.

Jack-in-the-Pulpit

Jack-in-the-pulpit (Arisaema triphyllum [formerly Arisaema atrorubens]) is also known as Indian-turnip because cooked corms were eaten by Native Americans.  A mature corm produces one or two large glossy compound leaves on stout fleshy stalks.  Typically, three smooth-edged leaflets emanate from a common point at the top of each leaf stem (photo 2), though leaves can occasionally have five leaflets (photo 3).  Leaflets, up to a foot long and up to 8 inches wide, are broadly oval to elliptic with tapering points.  Leaflets of both plants have pinnate venation which stops near leaf edges.

 Jack-in-the-Pulpit - Arisaema triphyllumPhoto 2:  Characteristic shape of Jack-in-the-pulpit’s compound leaves.  Typical plants have only three leaflets.  Note venation.

Jack-in-the-Pulpit - Arisaema triphyllumPhoto 3:  Occasional Jack-in-the-pulpit plants have leaves with five leaflets each.

The inflorescence, initially wrapped by stipules at the base of leaf or leaves, has a spathe (widened hood or pulpit) rising above the central protruding spadix (Jack) (photo 4).  Exterior of the spathe is usually green or purple and the inside usually striped greenish white (along veins that parallel flower stalk) and purple (between veins).  The lower portion of the spathe is a tube-like sheath wherein numerous tiny male and/or female flowers, tightly bound to the spadix, are hidden.  Structures on the spadix standing above male and female flowers are infertile.  Pollinating flies are trapped in the lower portion of the spathe (photo 5).

Jack-in-the-Pulpit - Arisaema triphyllumPhoto 4:  Inflorescence of Jack-in-the-Pulpit showing over-arching spathe and post-like spadix.

Jack-in-the-Pulpit - Arisaema triphyllumPhoto 5:  Developing berries of Jack-in-the-pulpit.  The spathe has begun to dry.  Insect carcasses litter the base of the spathe.

Green-Dragon

Green-dragon or dragon-root (Arisaema dracontium) is very similar to Jack-in-the pulpit, with main differences being in leaves and inflorescence.  Green-dragon usually has only one large compound leaf with 7 to 15 lance-shaped leaflets (photo 6).  Green-dragon has a greenish spathe that is less prominent and the spadix is considerably longer, thinner, and tapered, extending upward (the dragon’s tongue) around the top of the spathe (photo 7).  Mature green-dragon leaves have the central and largest leaflet unfurling first.  At the base of the central leaflet, other leaflets branch off, forming a semi-circle parallel to the ground [the dragon’s wings?] (photo 8).

Green Dragon - Arisaema dracontiumPhoto 6:  Leaves of green-dragon.  The largest central leaflet ties directly to the leaf stalk while other leaflets grow from a “branch” on either side. Note venation.

Arisaema dracontiumPhoto 7: Green-dragon inflorescence.  Spadix is several times longer than spathe. (Plant seen behind green-dragon is May-apple.)

Green Dragon - Arisaema dracontiumPhoto 8:  A new leaf and flower of green-dragon.  Leaf may suggest dragon’s wings.  (Plant seen behind green-dragon is celandine poppy.)

Article and photographs by ANPS member Sid Vogelpohl

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Neat Plant Alert – Scarlet Beardtongue

The recent ANPS field trip to Poison Springs Natural Area and nearby back roads was very productive! Trip leader Meredith York took us to see some great plants, many of which are rare in Arkansas.

The most spectacular sight of the day was without a doubt Scarlet Beardtongue (Penstemon murrayanus).

Scarlet Beardtongue - Penstemon murrayanus

Scarlet Beardtongue photographed along County Road 423 in Nevada County

Found only in Nevada and Ouachita counties in southwest Arkansas, Scarlet Beardtongue is more common to the southwest in the eastern half of Texas.

Scarlet Beardtongue - Penstemon murrayanus

Our largest Beardtongue – the blooming stalks can reach over 6 feet in height by the end of the bloom season

Scarlet Beardtongue - Penstemon murrayanus

The bright red flowers are a favorite of Ruby-throated hummingbirds

Article and photographs by ANPS member Eric Hunt

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