THE TRIUMFETTAS OF AFRICA. 237 
subsect. Paniculatæ, and frequently in Lappula they appear to be connected 
by numerous intermediate forms, which almost defy classification in the 
herbarium. The difficulty is enhanced by the incomplete nature of much of 
the material, identification being frequently uncertain in the absence of fruits. 
It 1s possible that some of the intermediate forms referred to may be hybrids, 
but there is no evidence of this. A satisfactory classification of the more 
critical species is probably unattainable without special work in the field. 
It seems desirable to summarize what little is known of the ecology of the 
African species. Most of them are shrubs, undershrubs, or perennial herbs, 
comparatively few being annuals. Among the latter is annua, which is a 
common weed of cultivated land. Most of the shrubby species are erect, but 
some, such as scandens, cordifolia var. Hollundii, and macrophylla, may become. 
climbers when growing in dense forest. The sharp tubercles on the stem of 
scandens, which is the most pronounced climber, have apparently been 
developed pari passu with the adoption of a climbing habit, as they do not 
occur on the stems of its nearest allies. 
As a rule, the species of one natural group belong to much the same 
ecologic type. T. procumbens and repens both have long procumbent rooting 
branches, and are characteristic plants of the Pescapræ formation of the 
Indo-Malayan seashore (Schimper, Indo-mal. Strandfl 78). Тһе whole 
section Lasiothriv inhabits dry open country, adapted for the dispersal by the 
wind of its light plumose fruits ; and the species belonging to the subsections 
are adapted to the conditions of the desert, savannah, or veld in which they 
grow, either by their shrubby habit, as in the Actinocarpæ, or by suffrutescent 
habit and a woody rhizome, as in the JDigitatee and Sonderiane, or by the 
development of a woody rhizome bearing annual above-ground shoots, as in 
the Paniculate. 
Many species occur in bushy places, or in clearings or sunny borders of 
woods, and some of these show a fair amount of adaptability to the surrounding 
conditions : thus tomentosa has been recorded from among bracken and in 
open grassy places, from the borders of woods and from forest; and cordi- 
folia (typica) from open places, woods, and forest. 
Many of the species appear to be represented only by scattered plants, 
whilst others, such as effusa, may occur in clumps. T. tomentosa and macro- 
phylla are both locally abundant, being among the commonest constituents of 
the bush at Marangu, German East Africa, according to Volkens. Finally, 
flavescens, which appears generally to oceur scattered, constitutes a distinct 
formation on the north-east end of Kidero Mt., German East Africa, where 
it is a bush 1 m. high, according to Jaeger. 
As regards pollination, but little is known. From observations by Schimper 
at Dschadscha, Abyssinia, it appears that the flowers of flavescens are visited 
by inumerable bees ; and Schefller noticed that they were much visited by a 
small beetle in British East Africa. 
