Desmanthus tatuhyensis


Scientific name

Desmanthus tatuhyensis  Hoehne

Subordinate taxa:
Desmanthus tatuhyensis Hoehne var. brevipes (B. L. Turner) Luckow
Desmanthus tatuhyensis Hoehne var. tatuhyensis
Closely related to D. acuminatus and may in fact be regarded as a variety of it.

Synonyms

    

Family/tribe

Family: Fabaceae (alt. Leguminosae) subfamily: Mimosoideae tribe: Mimoseae. Also placed in: Mimosaceae.

Common names

    

Morphological description

A small prostrate to erect perennial herb to 0.4 m tall, with 2-4 branches from the base.  Young stems green, strongly angular with corky ridges, sparsely haired along the midrib.  Older stems hairless, angular, green or brown.
Bipinnate leaf 2.3-7.5 cm long with 1-4 pairs of pinnae 21-42 mm long and with 19-38 pairs of leaflets/pinnae 3.0-4.2 mm long and 0.7-1.3 mm wide.  Petiole 5-14 mm long.  Persistent stipules 2.0-4.0 mm long with membranous wing opposite the petiole .
Small flowering heads (condensed spikes) 0.5-0.7 cm long, occur singly in leaf axils on very short peduncles (to 5 mm long).  Heads contain 7-9 flowers that may be perfect, functionally male or sterile.  Sterile flowers occur rarely, when present 1-2 occur at the base of the head.  Male flowers occur towards the base of the head above the sterile flowers, but below the perfect flowers and number 0-2.  Perfect flowers (5-8 in number) occur apically and are 1.8-2.8 mm long.  Fruiting stalks 0-1.0 cm long bear 1-11 pods.
Pods are linear , 3.1-5.0 cm long and 3.1-3.3 mm wide, opening along both margins, black -brown at maturity.
Seeds 7-18/pod, 1.9-2.6 x 1.5-2.2 mm, plump and ovate in shape and golden-brown in colour.

Distribution

Native to:
Var. tatuhyensis occurs in southeast Brazil, Paraguay, Argentina and Uruguay in dry grasslands, cleared fields and at roadsides at altitudes of 400-1,200 m.
Var. brevipes occurs in grasslands, beaches, roadsides and bay fronts in southern coastal Texas (USA), and in disturbed areas and roadsides in both Texas and the Chaco region of Argentina and Paraguay at altitudes of 0-1,150 m.
There is some doubt over the requirement for the varietal distinction as it is based on continuous variables.

Uses/applications

Not tested, but could be used to augment perennial native grass pastures. Some accessions may have particular application on acid soils.

Ecology

Soil requirements

Native to sandy or gravely soils, but also found on clay soils.

Moisture

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Adapted to moderately high rainfall environments with specimens collected from regions with mean annual rainfall of between 850 and  1,700 mm.

Temperature

Average annual temperatures in the native environment range from 20-26°C.

Light

May possess some shade tolerance because of its natural occurrence under low woodlands.

Reproductive development

Flowering and fruiting occurs from September through to March in south eastern Brazil and Paraguay.  Var. brevipes flowers and sets seed after rain in Texas from June to October with a peak in August.  In Argentina, flowering occurred in October, November and March.

Defoliation

No information available.

Fire

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No information available.

Agronomy

Establishment

Very limited evaluation has been conducted with D. tatuhyensis .  See requirements for other Desmanthus spp. as a guide.

Fertiliser

No information available.

Compatibility (with other species)

No information available.

Companion species

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Pests and diseases

No information available.

Ability to spread

No information available.

Weed potential

No information available.

Feeding value

Nutritive value

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Very limited evaluation has been conducted with D. tatuhyensis .  See values for other Desmanthus spp. as a guide.

Palatability/acceptability

No information available.

Toxicity

No information available.

Production potential

Dry matter

Accessions assessed in Australia were of low to moderate productivity.

Animal production

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No reports of animal production data were cited.

Genetics/breeding

No breeding programs have been undertaken, however D. tatuhyensis has been collected in conjunction with selection programs examining D. virgatus , D. pubescens and D. leptophyllus Chromosome number 2n = 28.

Seed production

No information available.

Herbicide effects

No information available.

Strengths

  • Appears to possess some tolerance of acid soil conditions.

Limitations

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  • Accessions evaluated to date were of low to moderate productivity.

Other comments

    

Selected references

Luckow, M. 1993. Monograph of Desmanthus (Leguminosae-Mimosoideae). Systematic Botany Monographs. Vol. 38. The American Society of Plant Taxonomists.

Internet links

Cultivars

Cultivars

Country/date released

Details

None released to date.          

Promising accessions

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Promising accessions

Country

Details

CPI 25840, 37538, 40073 are all D.  tatuhyensis var. tatuhyensis and morphologically  similar. Australia CPI 37538 is a small type that persisted strongly on an acid soil site at a humid, subtropical site in Australia (Gympie) where other Desmanthus accessions were chlorotic and weak.  Growth of CPI 37538 was not particularly vigorous, but its acid-soil tolerance is significant.