Desmodium sandwicense E. Meyer

Leguminosae

Synonyms

D. limense Hook.

Spanish clover (Hawaii), Sandwitch (the Philippines).

Erect or decumbent perennial herb, 20 to 100 cm tall, occasionally woody at the base; sometimes climbing by means of viscid pubescent recurved hairs on the stems and pods. Internodes of stem as much as 4 cm long. Stems red or green in colour, leaves trifoliate, glabrous above and with a conspicuous lighter irregular area around the midrib (occasionally absent), pubescent underneath, especially on veins, petioles and petiolules; ovate-lanceolate leaflets, 2 to 6 cm long. Inflorescence a terminal axillary viscid-pubescent raceme, 10 to 15 cm long. Flowers white to purple, becoming faded with age; standard with two conspicuous green areas near the base. Pod subsessile in the persistent calyx, commonly with eight reticulated joints about 4 mm long and slightly curved on the dorsal suture. Seed yellow olive-green to reddish brown, flat, about 2.5 mm long and 1.75 mm wide (Rotar, personal communication) .

Throughout Hawaiian islands to about 1 075 mm, occasionally to 1 800 m where rainfall is 750 mm or more.

Summer-growing perennial where moisture is available. Whiteman (1970) found the optimum temperature for growth of Desmodium spp. to be 30/25°C &177; 3°C for day/night temperatures. D. sandwicense is less affected by cold weather than D. uncinatum and D. intortum (aparines). Its altitude range is from sea level to a maximum of 1 800 m.
D. sandwicense needs an annual rainfall in excess of 750 mm. It is more drought-tolerant than other Desmodium spp., and Rotar (personal communication) states that it is valuable for germ-plasm because of this feature. It is not tolerant of flooding. It tolerates a wide range of soil conditions, growing on sands and clay loams with a pH range from acid to neutral.
It is somewhat specific in its Rhizobium requirements, and Norris (1967) recommends inoculation with the "Desmodium" strain, CB 627. In Hawaii the cowpea strain is satisfactory (Rotar, personal communication). Whiteman (1970) found that changes in nodulation of D. sandwicense during growth do not follow the pattern of steady increase and decline shown by D. intortum and D. uncinatum. The dry-matter production curve was very similar to the nodule weight curve.
Seed is broadcast or drilled into a well-prepared soil at a sowing depth of 1 to 1.5 cm and lightly covered. Sow just before the rains in summer at 1 to 2 kg. seed per hectare, with a dressing of fertilizer containing phosphorus, potash and micronutrients.
D. sandwicense is indeterminate in its flowering response and flowers on three occasions during the growing season in south-east Queensland (lat. 27°22'S): in early December, early February and late April (Whiteman, 1970) . It flowers in 45 to 50 days in Hawaii (Rotar, personal communication) .
It is capable of growing with tall grasses (which it climbs) and is not affected by normal light conditions. Combines well with Setaria, Paspalum and Panicum spp.
It has fairly good seedling vigour and fixes nitrogen well. It does not respond well to defoliation.
It is self-fertile, usually with some cross-fertilization. Chromosome number 2n = 22. Seed set is improved by tripping the flowers.
Jones, Davies and Waite (1967) grew D. sandwicense (CPI 18227 and CPI 18225) with Paspalum plicatulum at Samford in south-east Queensland. The legume only persisted for two years, yielding merely 390 kg./ha dry matter in the first year, and contributing 10 percent of the dry matter and 15.2 percent of the nitrogen to the mixture, increasing to 1 300 kg. DM/ha in the second year, which corresponded to 13 percent of the total dry matter and 27.8 percent of the nitrogen. It performed very poorly in comparison with siratro and lotononis. Horrell (1958) found it inferior in performance to D. uncinatum at Serere, Uganda, as did Anderson and Naveh (1968) in northern Tanzania. They harvested an average of 3 749 kg. DM/ha from three sites.
It is subject to little-leaf and to Xanthomonas sp. The rose beetle and cotton cushiony scale attack it in Hawaii (Rotar, personal communication). The main attribute of D. sandwicense is its drought resistance. It seeds too heavily, however, and has poor tolerance to grazing.