Angiosp : ^lonocotyledons — Palmae. XV. 



MONOCOTYLEDONS, a large section of Angiosperms collateral with 

 modern Dicots.. convergent onl}- in retention of an older phase of Monoclilaniydeous 

 state of floral organization, and comprising a large number of widely divergent 

 series expressing most advanced phases of specialization in some respects, and of 

 further reductions in others, in somatic organization as well as in floral construction. 

 The tree-phjla (Palms) have no cambial increase of timber, and the stems are 

 predominantly monaxial ; but this is counterbalanced by the iminense size of the 

 foliage-leaves, and freely-branched inflorescence-systems. All tend to the limiting 

 condition of a trimerous eucyclic type of flower — passing to extreme phases of reduc- 

 tion in anemophilous inflorescence-aggregates (Grasses), or to the extreme elaboration 

 of individual entomophilous floral mechanisms (Orchids). The single cotyledon of 

 the seedling, indicated as characteristic of the class as a whole, is comparable with 

 the single posterior 2-keeled prophyll of the vegetative laterals in many types, as 

 a specialized gamophyllous structure replacing two initial primordia. 



I. Palmae (128/1000), typically monaxial arboreal forms, with leaf-lamina 

 secondary on a hooded petiolate scale-base, plaited fan-wise and segmented by the 

 decay of strips of surface-tissue (palmate-type), to be subsequently elongated on a 

 rachis-growth (pinnate-type). Wholly entire leaves occur {Corypha; King Palm, 

 and ju\ enile states) ; bipinnation in Caryola ; basal pinnules are commonly spinous, 

 subserving xerophytic bud-protection of the apex ; the leaves spirally arranged, with 

 persistent leaf-bases (similarly protective), or alsstricted with clean annular scars. 



Inflorescatce-sy stems, terminal or axillary, retain older more generalized rami- 

 fication-schemes, to multibranched panicles (30 ft.) with thousands of flowers (to 

 600,000), or reduce to cymose systems on condensed spadix-growths : large pro- 

 tective bracts of leaf-base construction (spathes) may subserve protection of younger 

 parts or developing fruits. 



The growth-period is often monocarpic with T-par.icle. Lianoid forms present 

 extended internodes {Calamus) with spiny 'lora' as leaf-rachis or inflovescence-axis. 

 The monaxial stem may reduce to a rosette-habit, with crown of fronds in the 

 manner of a Cycad {P/wenix acaulis) or may become rhizomatous at the surface or 

 subterranean in the manner of advanced ferns {Ni'pa, swamp-type, Nannorhops, 

 desert xerophyte). 



Flowers, trimerous, and commonly much reduced, tending to dicliny with limit 

 in dioecism, fundamentally of eucyclic type, per. 3 -t- 3, and. 3-F3, gyn. 3, apocarpous 

 to typically syncarpous, with floral output reduced to i seed per loculus, and com- 

 monly restricted to i seed per flower in a berry or drupaceous fruit. The seeds 

 store fat in endosperm-tissue, or celluloses in its walls, the endosperm simple, in- 

 complete with cavity, or ' ruminated '. The stems may store large reserves of starch. 

 Xeromorphic specializations of all kinds commonly prevail in all vegetative and 

 reproductive parts. The range of type in such an isolated series is so great that 

 classification by one character more than another is wholly empirical. Forms with 

 older palmate leaves seem more archaic on the whole, as comparatively few and 

 residual, though advanced in other respects. The family is essentially tropical of 

 moist regions but may range to dry tracts {A\7wior//ops) with external xeromorphic 

 details. Chamaerops humilis, a bushy form, 20 ft., alone extends to Europe (with 

 Phoenix as introduction in Greece, &c.). Hardy Chinese forms will flow^er in the 

 open in S. of England. 



Phoenix dactylifera, Date Palm of SW. Asia and Sahara, to 120 ft., monaxial 

 with pinnate foliage (7-12 ft.), stem clothed with old leaf-bases, dioecious. In- 

 florescence much branched, axillary ; staminate flower with 6 stamens ; carpellary 

 flower of 3 -h 3 perianth, inner series protective, 5 mm., and 3 carpels, apocarpous 

 with distinct stigmas. Fruit as sherries, 1-3 in., each with i elongated seed (i in.); 



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