482 PALMAR 



Palmae (EP., BH.}. Monocots. (Principes; Calycinae BH.}. 130 

 gen., 1 200 sp. trop. and subtrop. ; most of the gen. well localised in 

 the various floral regions, the chief exceptions being Cocos nudfera, 

 Elaeis guineensis and Raphia vinifera. The palms form a char, 

 feature of trop. veg. The veg. habit is familiar a crown of 1. at the 

 end of an unbranched stem (Hyphaene is branched). The stem ex- 

 hibits various forms ; some palms, e.g. Nipa, Phytelephas, have a short 

 rhiz. or stock bearing ' radical' leaves and often branching below ground; 

 some, e.g. Geonoma, Calamus, Desmoncus, have a thin reed-like stem 

 with long internodes (the two latter are climbers) ; others again have 

 a tall stem with a crown of 1. at the top. The stem is often covered 

 with the remains of old leaf-sheaths, or is thorny. Its height may reach 

 150 feet in some, and it grows slowly in thickness. At the base the 

 stem is usu. conically thickened or provided with buttress roots; this 

 gives the necessary mechanical rigidity. The stems of Cocos and other 

 palms are curved instead of straight; this appears to be due to reaction 

 to light. 



The 1. is very characteristic; the only closely similar 1. is that of 

 Carludovica, though those of Cycads and some tree ferns have a super- 

 ficial likeness. Some have palmate (fan) 1., some pinnate (feather) 1., 

 but this structure arises by a development unlike that which gives rise 

 to these forms in Dicots. and more like that in Araceae. The 1. is usu. 

 very large, and at the base of the petiole is a sheath, which makes a 

 firmer attachment to the stem than a mere articulation. The sheath 

 contains many bundles of fibres, which remain after the decay of the 

 softer tissues. The pinnae are folded where they meet the main stalk 

 of the 1., sometimes upwards (induplicate, V in section), sometimes 

 downwards (reduplicate, /\ in section) ; these chars, are important in 

 classification. The 1. emerges from the bud in an almost vertical line 

 and thus escapes excessive radiation and transpiration. The palms are 

 pronounced sun-plants, and show xero. chars, in their 1. The leaf- 

 surface is glossy with a thick cuticle, and is rarely arranged 1 to the 

 incident rays. Often the 1. is corrugated, or placed at an angle by the 

 twisting or upward slope of the stalk; sometimes the leaflets slope 

 upwards, and so on. 



Infl. usu. very large and much branched. In Corypha and others 

 it is term., its production being a mark of the end of the life of the 

 plant (</. Agave), but usu. it is axillary; sometimes in the axils of the 

 current 1., sometimes lower on the stem. The branching is racemose 

 and the fls. are often embedded in the axis; the whole is often termed 

 a spadix. It is enclosed in a spathe of several 1. and emerges when 

 the fls. are ready to open. Some are dicec., some moncec., in the 

 latter case often with the fls. in groups (small dichasia) of 3, one ? 

 between two <f . 



The fl. has usu. the formula P 3 + 3, A 3 + 3, G 3 or (3). P homo- 

 chlam., varying in texture. G (3) i-loc. or 3-loc., with 3 or some- 

 times i, anatr. ovules (rarely semi-anatr., or orthotr.). Some are 

 wind-pollinated, others are entomoph. 



Fr. a berry or drupe ; in the latter' case the endocarp usu. united 

 to the seed. Fr. in in covered with dry woody scales. Endosperm 

 large; in date, vegetable ivory, &c., it is very hard, the non-nitro- 



