CASSIA 367 



(see under 'natural reproduction ', p. 368). It is found on a variety of geo- 

 logical formations and will grow on poor shallow soil, as on the dry outer 

 slopes of the Himalaya. In climatic requirements it shows a wide range. In 

 its natural habitat the absolute maximum shade temperature varies from 

 100 to 120 F., the absolute minimum from 25 to 65 F., and the normal 

 rainfall from 20 to 120 in. or more. 



Leaf-shedding, flowering, and fruiting. The tree is leafless for 

 a very short time, or hardly at all, between March and May, the new leaves 

 appearing in April-May ; these are bright green or sometimes a beautiful 

 rich copper colour. The long pendulous racemes of large bright yellow flowers 

 appear chiefly with the new leaves from April to June, but it is no uncommon 

 thing to find the tree in flower even as late as September, particularly in dry 

 years. The long cylindrical pods develop rapidly, reaching almost full length 

 but not full thickness by October, when they are still soft and green. By 

 November they are full-sized but still green and unripe ; they commence 

 ripening in December and continue ripening from January till March or April. 

 The ripe pods are 1-2 ft. long or sometimes more, 0-75-1 in. in diameter, pendu- 

 lous, cylindrical, dark brown, smooth, hard, indehiscent, septate into numerous 

 one-seeded cells, the seeds being embedded in a dark brown sweetish pulp 

 which is a strong purgative. The ripe pods hang for some time on the tree, 

 commencing to fall about April-May, and continuing to fall in the following 

 months : old pods may often be found on the trees in September or later 

 along with the new half-grown green pods. 



The seeds (Fig. 145, a) are 0-3-0-4 in. by 0-2-0-3 in., ovate, compressed, 

 light brown, hard, smooth, shiny, with a moderately hard testa and a horny 

 albumen. About 2,500 weigh 1 lb. Like many other hard leguminous seeds, 

 those of Cassia Fistula take some time to germinate, some lying a whole year 

 in the ground before doing so, even if regularly watered. Boiling the seeds 

 for about five minutes before sowing has been found to give very good results 

 in stimulating germination. ^ Tests carried out at Dehra Dun showed that 

 the seeds retain their vitality unimpaired for at least two years. It was found 

 that seed from pods one year old germinated more quickly than that from 

 fresh pods, though the percentage of sound seeds in the former may be low 

 owing to insect attacks. As regards the identity of the insects which do much 

 damage by attacking the seeds within the pods, specimens of infected pods 

 collected in the Siwaliks in December 1910 were kept under observation ; 

 from these were bred out (1) from May 4 to June 5, 1911, moths identified 

 as Trachylepiclia fructicassiella, Rag., and (2) from May 4 to 13, 1911, beetles 

 identified as Caryoborus gonagra, Fabr.- 



Germination (Fig. 145, b-e). Epigeous. The radicle issues and the 

 hypocotyl arches slightly, raising above ground the cotyledons enclosed in the 

 testa, which soon falls, along with the albumen, when the cotyledons expand. 



The seedling (Fig. 145). 



Roots : primary root long, terete, tapering, wiry, yellow turning brown, 

 glabrous : lateral roots numerous, fibrous, distributed down main root : 



1 Forest Report of Bihar and Orissa, 1917-18. 



2 Lefroy, Indian Insect Life, pp. 351 and 509. See also Ind. Mus. Notes, iv. 106, for damage 

 by the tortricid moth Cryptophebia carpophaga, Wlsm. 



