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Parish flatsedge, Parish's flatsedge, Parish's nutgrass

ballast sedge, inflated-scale flatsedge

Habit Herbs, annual, cespitose. Herbs, perennial, cespitose, rhizomatous.
Culms

trigonous, 5–25 cm × 1–1.5 mm, glabrous.

trigonous, 20–100 cm × 0.8–2.5 mm, glabrous.

Leaves

5–10, V-shaped to flanged V-shaped, 10–70(–90) cm × 2–7 mm, margins and midribs scabridulous or glabrous.

Inflorescences

spikes loosely ovoid, 15–25 mm wide;

rays 1–6, 2–7 cm;

bracts 2–5, 3–20 cm, ascending;

rachilla deciduous, winged.

spikes 1(–6), densely cylindric, 6–30 × 5–11 mm;

rays 3–12, 0.4–5(–7) cm;

rays and rachis glabrous; usually only 1–2 spikes of inflorescence on elongate rays, other spikes sessile or nearly so;

bracts 4–7, horizontal to slightly ascending, 1–16 cm × 0.5–4 mm;

rachilla deciduous, wings persistent, 0.5 mm wide.

Spikelets

5–30, linear, flattened, 6–22 × 1.5–2.2 mm;

floral scales ± deciduous, (4–)8–12, red, reddish purple, or reddish brown, medially green, elliptic, laterally 2–4-ribbed, 2.3–3.1 × 1.2–2 mm, apex acute to obtuse.

20–80, ellipsoid, roughly quadrangular, 3–5 × 1–1.4 mm;

floral scales 1–2(–4), appressed, stramineous to golden brown, often red-speckled, medially greenish, 9-ribbed, elliptic to ovate, 2.4–3.4 × 1.8–2.6 mm, apex obtuse.

Flowers

anthers 0.3–0.4 mm;

styles 1 mm;

stigmas 1.3–1.6 mm.

anthers 0.4–0.6 mm;

styles 0.7–1.1 mm;

stigmas 1.4–2.1 mm.

Achenes

brown to dark purplish brown, broadly ellipsoid, 1–1.3 × 0.6–0.9 mm, surfaces puncticulate.

dark brown to reddish brown, sessile, broadly ellipsoid, 1.8–2.1 × 0.8–1 mm, apex apiculate, surfaces glabrous to finely puncticulate.

Cyperus parishii

Cyperus aggregatus

Phenology Fruiting summer. Fruiting mid summer–fall (Jul–Oct).
Habitat Stream banks, desert washes, arroyos, roadsides Dry roadsides, pastures, thickets
Elevation 0 800 m (0 2600 ft) 0–500 m (0–1600 ft)
Distribution
from FNA
AZ; CA; NM
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; LA; MS; NJ; NM; OR; PA; TX; Mexico; Central America; South America [Introduced, Australia]
[WildflowerSearch map]
[BONAP county map]
Discussion

The records of Cyperus aggregatus in New Jersey, Oregon, and Pennsylvania represent introductions from ballast.

The closely related Mexican and Central American Cyperus regiomontanus Britton has been collected once as an adventive or waif in southern California. It is distinguished from C. aggregatus by its silvery green, subulate-lanceolate spikelets and achenes that are only 0.4–0.6 mm wide.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 170. FNA vol. 23.
Parent taxa Cyperaceae > Cyperus > subg. Cyperus Cyperaceae > Cyperus > subg. Cyperus
Sibling taxa
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
C. acuminatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
Synonyms C. congestus var. parishii Mariscus aggregatus, C. cayennensis, C. flavus, C. flavus var. aggregatus, C. flavus var. laevis, Kyllinga cayennensis, Kyllinga squarrosa, Mariscus flavus, Mariscus laevis
Name authority Britton ex Parish: Bull. S. Calif. Acad. Sci. 3: 52, plate 3. (1904) (Willdenow) Endlicher: Cat. Horti Vindob. 1: 93. (1842)
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