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Digitaria cruciata

(Crabgrass)

Interesting Facts

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Common Names

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Common Names in English:

Crabgrass

Description

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Genus Digitaria

Annual or perennial . Culms erect or decumbent , occasionally stoloniferous . Leaf blades linear or linear-lanceolate; ligule membranous. Inflorescence of digitately arranged racemes , sometimes on a short axis or with secondary branchlets , very rarely paniculate ; spikelets usually in groups of 2-3(-4), imbricate to effuse, the latter often on notably long and unequal pedicels. Spikelets puberulous to villous , typically in stripes between the well-defined veins, rarely glabrous ; lower glume absent or reduced to a little scale up to 1/4 spikelet length; upper glume variable; lower lemma usually ± equal to spikelet; upper floret pallid to black, apex subacute to acuminate, rarely apiculate . x = 9.

About 250 species:tropical and warm-temperate regions of the world; 22 species (three endemic) in China.

Digitaria has been traditionally divided on the nature of the spikelet hairs, which may be clavate , capitate, verrucose (warty, appearing beaded), or with crooked tips . As good magnification is required to see these features, the grouping of the spikelets on the raceme is a more practical aid to identification. Many species have regularly paired spikelets, which present no difficulty. In those species where the spikelets are grouped in clusters of 3 or more, care must be taken, as often the longest pedicel of a group is partially fused to the rachis so that the spikelets appear alternately paired and single, or sometimes one spikelet may be vestigial, or the spikelets may be paired toward the raceme tips.

Many species are very variable in spikelet pubescence and lemma nervation, even within a single raceme. Additionally, there are a number of complexes of intergrading species, so intermediates may occasionally be encountered. This has led to the publication of many superfluous names .[1]

Physical Description

Species Digitaria cruciata

Annual . Culms decumbent at base , branching and rooting at lower nodes, 30-100 cm tall, nodes thinly hispid . Leaf sheaths glabrous or hispid; leaf blades linear-lanceolate, 5-20 × 0.3-1 cm, papillose-hispid on both surfaces or adaxial surface glabrous, margins thickened, undulate , scabrous ; ligule 1-2.5 mm. Inflorescence subdigitate, axis 1-5 cm; racemes 5-8, 3-15 cm; spikelets paired , imbricate; rachis winged , ca. 1 mm broad, midrib triquetrous , margins scabrous. Spikelets plumply elliptic-oblong, 2.5-3 mm; lower glume minute, veinless; upper glume broadly ovate , 1/3 as long as spikelet, 3-veined, subglabrous, margins membranous, apex broadly obtuse ; lower lemma slightly shorter than upper lemma, 7-veined with intervein spaces nearly equidistant , glabrous or margins pilose ; upper lemma pale purplish gray at maturity, apex abruptly apiculate , exserted from spikelet. Fl. and fr. Jun-Oct. 2n = 18, 36, 72. [source]

This species is a common weed in the Himalayan region, generally occurring at higher altitudes than other members of the Digitaria ciliaris complex . It is usually clearly distinguished by its relatively broad spikelets with a short, rounded upper glume and apiculate apex to the fertile floret. [source]

Digitaria cruciata var. esculenta Bor is a minor cereal cultivated in the Khasi hills of NE India. It has longer racemes than the wild form, and a turgid , persistent grain. The name has been misapplied to wild-growing plants in Xizang (Lhasa). [source]

Habit: Graminoid

Habitat

Upland grasslands; 1000-2700 m [2].

Taxonomy

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Synonyms

Panicum cruciatum Nees Ex Steudel • Paspalum sanguinale (Linnaeus) Lamarck Var. cruciatum (Nees Ex Steudel) J. D. Hooker.

Notes

Name Status: Accepted Name .

Last scrutiny: 15-Mar-2000

Similar Species

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Members of the genus Digitaria

ZipcodeZoo has pages for 53 species, subspecies, varieties, forms, and cultivars in this genus:

D. abyssinica (African Couchgrass) · D. arenicola (Fall Witchgrass) · D. argillacea (Tropical Crabgrass) · D. bicornis (Asia Crabgrass) · D. californica (Arizona Cottontop) · D. ciliaris (Fingergrass) · D. cognata (Carolina Cottontop) · D. cognata var. cognata (Carolina Crabgrass) · D. cognata var. pubiflora (Carolina Crabgrass) · D. cruciata (Crabgrass) · D. diagonalis (Brown-Seeded Finger Grass) · D. didactyla (Crabgrass) · D. dolichophylla (Caribbean Crabgrass) · D. eggersii (Eggers' Crabgrass) · D. eriantha (Pangola Grass) · D. eriantha subsp. eriantha (Crabgrass) · D. eriantha subsp. pentzii (Woolly Fingergrass) · D. exilis (Fonio) · D. filiformis (Slender Crabgrass) · D. floridana (Florida Crabgrass) · D. fuscescens (Yellow Crabgrass) · D. gracillima (Long-Leaf Crabgrass) · D. henryi (Henry´s Crabgrass) · D. hitchcockii (Short-Leaf Crabgrass) · D. horizontalis (Jamaica Crabgrass) · D. iburua (Black Fonio) · D. insularis (Sourgrass) · D. ischaemum (Small Crabgrass) · D. ischaemum var. ischaemum (Small Crabgrass) · D. longiflora (India Crabgrass) · D. milanjiana (Madagascar Crabgrass) · D. natalensis (Natal Crabgrass) · D. nuda (Naked Crabgrass) · D. panicea (Millet Crabgrass) · D. patens (Texas Cottontop) · D. pauciflora (Florida Pineland Crabgrass) · D. pubiflora (Carolina Crabgrass) · D. radicosa (Trailing Crabgrass) · D. sanguinalis (Crabgrass) · D. seriata (Crabgrass) · D. serotina (Blanket Crabgrass) · D. setigera (East Indian Crabgrass) · D. setivalva (Crabgrass) · D. similis (Roadside Crabgrass) · D. simpsonii (Isle-Of-Pines Crabgrass) · D. swalleniana (Swallen's Crabgrass) · D. ternata (Black-Seeded Crabgrass) · D. texana (Texas Crabgrass) · D. tomentosa (Woolly Crabgrass) · D. umfolozi (Crabgrass) · D. velutina (Annual Couchgrass) · D. villosa (Shaggy Crabgrass) · D. violascens (Violet Crabgrass)

More Info

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Further Reading

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Notes

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Contributors

Identifiers

Footnotes

  1. Shou-liang Chen & Sylvia M. Phillips "Digitaria". in Flora of China Vol. 22 Page 1, 500, 539. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. "Digitaria cruciata". in Flora of China Vol. 22 Page 540, 543. Missouri Botanical Garden Press. Online at EFloras.org. [back]
Last Revised: 7/15/2012