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Troublesome sedge is superficially similar to crested sedge (C. cristatella) but with fewer, less spiky spikelets, and with perigynia less crowded. Two to five (rarely six) spikelets are crowded along an inflorescence at the tip of the culm, each 6-15 mm long and 5-10 mm wide. The perigynia are rounded at tip and base, tapering distally to a blunt point, each with a darker green, winged margin and a lighter center. Staminate (male) perigynia are relatively few and located at the base of the spikelets; most of the perigynia are pistillate (female). At the base of the lowermost spikelet is a thin, bristle-like, usually short bract. The left side of the image shows a young inflorescence; the right side shows a mature inflorescence post-fertilization.

Carex

Carex molesta

troublesome sedge [Blooms: May-Jun]

Two prickly sedge inflorescences photographed about a month apart. Fertile culms bear an apical inflorescence from 2-4" long bearing several short spikelets with a distinctly spikey appearance; the spikelets are initially light green (left image) but turn gold (right image) to brown as they mature. Each spikelet has a needle-like bract at its base (longest in the lowermost spikelet); the spikelet has a few staminate (male) perigynia apically but the majority of the perigynia are pistillate.

Carex

Carex stipata

prickly sedge [Blooms: May-Jun]

Pecan trees have separate male and female flowers on the same tree. The staminate (male) catkins droop from short spurs on the twigs; they typically develop in groups of three and are about 4-6" long with numerous staminate florets along the catkin. Individual staminate florets have a three lobed bractlet arising from their base that shelter the 4-6 stamens that hang beneath it; the middle lobe is the longer of the three lobes. The pistillate (female) spikes develop at the tips of a subset of the twigs, each spike bearing 3-10 greenish, pistillate florets; the florets are 1/4" long and 1/8" across. Each pistillate floret contains a short, tubular calyx, four bractlets of unequal sizes, and a pistil with two feathery stigmas. Each bractlet has four erect to spreading, lance-shaped lobes. The pistillate florets are wind pollinated. Fertilized florets transform into 2-6 greenish fruits (nuts in a husk) in a cluster, each with four short wings; when mature, the ovoid fruits are about 2" long and 1" across, brown or black in color; the husks partially divide into four segments along the wings, releasing the nut. Pecan is typically a bottomland tree that lives in river valleys but can grow in any rich, moist, well-drained soil. The leaves of black walnut and pecan have a similar number of leaflets in their odd-pinnate leaves, but the fruits are completely different. According to the Arnold Arboretum at Harvard, pecan trees (Carya illinoinensis) can live for over 300 years. For some reason, Carya illinoinensis is the state tree of ...... Texas.

Carya

Carya illinoinensis

pecan [Blooms: Jun-Aug]

Common hackberry flowers may be staminate (male), pistillate (female), or perfect (both), all on the same tree. Flowers are about 1/4" across and bloom before the leaves open, often high in the tree (thus, I have no pictures yet). All flowers are wind-pollinated, yellowish-green with 4-6 spreading sepals joined at their bases; there are no petals. Male flowers have 4-5 stamens with green or yellow-brown anthers; female flowers have a green ovary with a large two-part, densely fuzzy style like an umbrella beneath the ovary. Perfect flowers have both.

Celtis

Celtis occidentalis

common hackberry [Blooms: Apr-May]

Partridge pea flowers are ~1" across, noticeably asymmetric, with five yellow petals with red blotches at their base; the lowermost petal is about twice the size of the other petals. One of the lateral petals curls around the stamens. There are ten reddish-purple stamens and a single greenish-yellow style (longer than the stamens) that curves upward towards the tip; nine smaller stamens lie on one side of the style and one larger stamen on the other.

Chamaecrista

Chamaecrista fasciculata

partridge pea [Blooms: Jul-Oct]

Lamb's quarters produces inconspicuous star-shaped, yellow-green flowers, <1/8" across, sessile on flower stalks in round, tight clusters; the flowers have no petals, five stamens with yellow anthers, and a single divided style at the tip of a round, green ovary, all cupped in a five-lobed, mealy-white, calyx. The flowers are wind-pollinated and can aggravate hay fever symptoms.

Chenopodium

Chenopodium album

lamb's quarters [Blooms: Jul-Sep]

Lance-leafed coreopsis flowerheads are 2-3" across; they have about eight broad, yellow ray florets with 3-5 (usually four) bold, sawtooth lobes at their tips (that may also be subdivided); the numerous disk florets are also yellow, tubular, about 1/4" long with 4-5 tiny lobes.

Coreopsis

Coreopsis lanceolata

lance-leafed coreopsis [Blooms: May-Jun]

Prairie coreopsis flowerheads occur alone or in pairs on 1/2-2" long peduncles attached to the ends of stems. Each flowerhead is about 2" across with 8-12 ray florets; two prominent longitudinal veins divide each ray floret petal into thirds. The disc florets are tubular with 4-5 lobes; they are initially yellow, but turn brownish with age.

Coreopsis

Coreopsis palmata

prairie coreopsis [Blooms: Jun-Jul]

Plains coreopsis flowers are 1-2" across, with 6-12 (usually 8) ray florets, each with three lobes at their tips (center largest). The ray florets are sterile, typically yellow at their tips, transitioning abruptly to a maroon color more basally. The disk florets are perfect (have both anthers and pistils), reddish-brown to maroon with the florets at the edge of the disc with bright yellow highlights (either the anthers on the fused stamens or the split stigma of the pistils); individual florets have four teeth/lobes. The involucre of the flowerhead is often reddish-tinged, particularly obvious when cupping the developing seedhead.

Coreopsis

Coreopsis tinctoria

plains coreopsis [Blooms: Jun-Oct]

Tall coreopsis flowerheads arise from peduncles up to 10" long; the flowerheads are 1.5-2" across with eight sterile, yellow ray florets (each with two deep folds that divide the ray florets longitudinally into thirds) and numerous reddish-purple, fertile disk florets. The corollas of the disc florets are tubular, with 4-5 triangular lobes at their tips, and about 5 mm (~1/4") long; each has five stamens (fused together at their tips) with yellow anthers, and a single bifurcated style with pointed tips.

Coreopsis

Coreopsis tripteris

tall coreopsis [Blooms: Aug-Sep]

Whorled coreopsis' flowerheads are a bright golden yellow, 1-2" across, with eight yellow, elongate egg-shaped ray flowers and numerous (30-40) yellow disk flowers.

Coreopsis

Coreopsis verticillata

whorled coreopsis [Blooms: Jun-Sep]

Cornelian cherry dogwood is a European exotic that has been planted in Jackson Park. Flowers appear in umbels before the leaves emerge. The flowers are small (1/8"), with four bright yellow, lance-shaped petals, four stamens, and a cone-shaped, hairy receptacle; the single pistil emerges from the center of the ovaries. The fruit is an oblong, dark red drupe about an inch long.

Cornus

Cornus mas

Cornelian cherry dogwood [Blooms: Apr-?]

Narrow-leaf hawksbeard is a weedy-looking plant that reaches a size of 8-40". Flowers occur in a panicle (usually arising from a leaf axil) with up to 20 dandelion-like flowerheads. Individual flowerheads are about 1" across with 30-70 yellow ray florets (the "petals"); beneath the ray florets are two layers of green bracts — an inner layer of 12-15 3/8" long, sharply-pointed, keeled bracts covered in wooly or short stiff hairs and an outer layer of bracts half the length of the inner layer, sometimes ridged, with hairs like the inner layer. Narrow-leaf hawksbeard can be distinguished from similar dandelion-like flowers (Crepis pulchera, Crepis capillaris, and various sowthistles and hawksweeds) by the presence of auricles on the stem leaves and a layer of appressed hairs on the inside surface of the inner bracts, best seen with a magnifier.

Crepis

Crepis tectorum

narrow-leaf hawksbeard [Blooms: May-?]

Yellow nut sedge flower spikes are 2-3" long with spikelets sticking out at 90° to the axis and 90° to each other around the axis (producing four somewhat irregular rows down the axis). The axis itself is flattened with narrow wings. Individual spikelets are 1/2-3/4" long, yellow- or golden-brown, flattened, with from10-30, 2-3 mm long scales, each covering a floret. Each floret has a white, tripartite style with curly ends (the stigmas) and three stamens with yellowish-brown anthers; the flowers are wind pollinated.

Cyperus

Cyperus esculentus

yellow nut sedge [Blooms: Aug-?]

Shrubby cinquefoil flowers are 3/4-1.5" across, bright yellow, with petals that are circular and overlap, 15-20 stamens with golden anthers, and numerous pistils clumped in the center. The five sepals are largely hidden behind the petals; only the sepal's tips protrude.

Dasiphora

Dasiphora fruticosa

shrubby cinquefoil [Blooms: May-Jul]

Mullein foxglove has an odd-looking but very attractive flower that always makes me think of Burt Lahr's Cowardly Lion in the (1939) Wizard of Oz. Individual flowers are about 1/2-3/4" long and across with a basal green calyx decorated with five blunt teeth. The bright yellow, tubular corolla terminates in five spreading lobes; the upper two lobes are reflected backwards, while the lower three lobes (presumably) function as a landing pad for pollinators (mostly bumblebees). From the front, the opening into the corolla is largely obscured by numerous fine yellow hairs that tend to hide the stamens (present in two distinct lengths) and the single style with a two-lobed stigma.

Dasistoma

Dasistoma macrophylla

mullein foxglove [Blooms: Jul-Aug]

Northern bush honeysuckle flowers occur in clusters of 2-7 arising from leaf axils or at the tips of year-old branches; the flowers are initially yellow but they turn orange-red with age. The flowers are funnel-shaped, 1/2-3/4" long, hairy on the inside, with four slender lobes and a fifth, wider and darker lobe; the base of the flower is surrounded by five triangular sepals as long as the floral tube. The five stamens are densely hairy with yellow anthers; the style is long, slender, green, with a dome-like stigma.

Diervilla

Diervilla lonicera

northern bush honeysuckle [Blooms: May-Jul]

Annual wallrocket flowers occur on the tips of the stems. Each flower has four bright-yellow, oblong petals about 1/4" long with rounded tips; five light-green stamens with yellow anthers; and a green, stout pistil with an expanded, rough-textured stigma. The fruits are elongate (3/4-1"), narrow (1.5-2.5 mm), cylindrical siliques.

Diplotaxis

Diplotaxis muralis

annual wallrocket [Blooms: May-Oct]