ZANTEDESCHIA 695 



Yerba buena, Micromeria ; -mate, Ilex paraguensis A. St Hil. 



Yew, Taxus baccata L. 



Ylang-ylang, Cananga odorata Hook. f. 



Yoania Maxim. Orchidaceae (n. -2). i Japan. 



Yorkshire fog, Holcus. 



Young fustic, Rhus Cotinus L. 



Youngia Cass. = Crepis Vaill. p.p. (Comp.). 



Ypsilandra F ranch. Liliaceae (i). i Tibet. 



Yuca, cassava, Manihot utilissima Pohl, &c. 



Yucca Dill, ex L. Liliaceae (vi). 30 S. U.S., Mexico. &c. Many 

 cult. orn. (Adam's needle). Stem short, growing in thickness, and 

 branching occasionally (cf. Dracaena) ; at the end is a rosette of 

 fleshy and pointed 1. Fls. large, white, in panicle. Remarkable 

 mode of pollination (for details and figures see Riley in yd Ann. 

 Rep. Missouri Bot. Gdn. 1892). This is one of the few cases of 

 mutual dependence and adaptation of a single fl. and a single insect 

 Pronuba, a moth. The fl. emits its perfume esp. at night, and is then 

 visited by the moths. The female has a long ovipositor with which 

 she can penetrate the tissue of the ovary of the fl., arid possesses 

 peculiar prehensile, spinous, maxillary tentacles confined to the genus. 

 She begins soon after dark, collecting a load of pollen, and shaping 

 it into a pellet about thrice as large as her head. She then flies to 

 another fl. and deposits a few eggs in the ovary, piercing its wall 

 with her ovipositor. Having done this she climbs to the top and 

 presses the ball of pollen into the stigma. The ovules are thus ferti- 

 lised, and are so numerous that there are plenty for the larvae to feed 

 upon and also to repr. the plant. 



The leaves of Y. filamentosa L. and other sp. furnish an excellent 

 fibre (cf. Agave). 



Zaa Baill. (Tabebuia p.p.). Bignoniaceae (4). i Madag. 



Zacintha (Tourn.) L., Gaertn. Compositae (13). i Medit. 



Zaczatea Baill. (Raphiacme EP.). Asclepiadaceae (i). i Angola. 



Zahlbrucknera Reichb. Saxifragaceae (i). i E. Eur. 



Zalacca Rumph. Palmae (in). 10 Indomal. Fr. ed. 



Zalaccella Becc. (Calamus p.p.). Palmae (in. 2). i Cochinchina. 



Zaluzania Pers. Compositae (5). 10 C. Am. 



Zaluzianskya F. W. Schmidt. " Scrophulariaceae (n. 5). 20 S. Afr. 



Zamia L. Cycadaceae (see fam. for gen. char.). 30 trop Am. 



Zamioculcas Schott. Araceae (i). i E. trop. Afr. L. pinnate. 

 Zanlia Hiern. Burseraceae. i Angola. 



Zannicnellia Mich, ex L. Potamogetonaceae. i cosmop., Z. palitslris 

 L., in fresh or brackish water. Fls. monoec. ; $ term.; from the 

 axil of its lower bracteole springs the 3 . From the axil of the 

 upper a new branch may arise, bearing ? and 3 fls. again. The 

 3 fl consists of i or 2 sta., the ? of usu. 4 cpls., surrounded by a 

 small cup-like P. Pollination under water as in Zostera, but the 

 pollen is spherical. 



Zanonia Linn. Cucurbitaceae (i). i Indomal., Z. indica L., Z. ma- 

 crocarpa Blume. The latter has enormous flat winged seeds, re- 

 markably like those of many Bignoniaceae. 

 Zantedeschia Spreng. (Richardia Kunth, q.v.}. Araceae (v). 10 S. Afr. 



