Chapter VII 

 BYBLIS 



Occurrence. — Appearance and systematic position. — Habitat. — Structure. — Func- 

 tions of the glands. 



Byhlis is a genus confined to western Australia, where it is endemic. 

 There are two species, B. linifolia Salisb. and B. gigantea Lindl., the 

 latter being much the larger plant, one about 50 cm. tall. It is a half- 

 shrub in habit, consisting of a woody rhizome bearing in any one 

 season the dying parts of the previous and the growing ones of the 

 present season (zj - — i). These consist usually of a single chief stem 

 with one to three branches from near the base, all bearing long (1-2 

 dm.) linear leaves, clothed with numerous stalked mucilage glands. 

 The color, a yellow-green, is characteristic, and the surface is charged with 

 numerous ghstening mucilage droplets. The flowers, raised on axillary 

 peduncles, are violet or rose colored, have a deeply five lobed rotate 

 corolla, which appears superficially as pol}^etalous, the lobes alter- 

 nating with five oval attenuate sepals and with the five stamens. The 

 systematic position of this plant has not been at all clear. Planchon 

 (1848) and Bentham (Flora australiensis 2:469) believed that it is re- 

 lated to the Pittosporaceae rather than to the Droseraceae. Later 

 Lang, stressing too much its sympetaly, advanced reasons for its re- 

 lation to Pinguicula and its inclusion within the Lentibulariaceae, while 

 more recently Domin (1922) has placed it in a new family, the Bybli- 

 daceae, of which B. linifolia is the type. 



Byhlis gigantea was found growing abundantly in sandy, swampy 

 places in the Swan River district not far from Perth, where also are 

 to be found very characteristic species of Polypompholyx, (P. tenella 

 and multifida) and the peculiar Australian species of Utricularia, U. 

 Menziesii, Hookeri, etc., and all, except Polypompholyx tenella, confined 

 to W. Australia. Byhlis gigantea is, however, to be found in drier and 

 better drained parts of such swamps, as for example at Cannington 

 where it grows around the base of a low hillock on which stood a house, 

 and not, as Ross suggests, in very wet places on the banks of streams. 

 The substrate was a coarse quartz sand with some admixture of fine 

 white or yellow clay, and little humus. Specimens of Byhlis linifolia 

 were received from N. E. Arnhem Land where it was found growing 

 "around rocky pools in the bed of a river". 



The stem arises from a slender rhizome with triarch (Lang) or, as 

 I have observed, diarch roots often showing a considerable degree of 

 secondary thickening with a thick cortex loaded with starch and tannin- 

 emulsion-colloid (Lloyd 191 i). Both of these may be regarded as 

 storage material. From the perennating rootstock arises the new an- 

 nual stem with its appendages, which are secondary branches, leaves 

 and long peduncled flowers. All these parts are clothed with two kinds 

 of glands, sessile and stalked. In aU parts except the sepals, the 

 epidermis is composed of elongated straight-walled cells, all of which 



