244 POLEMOXIACE& [PoLEMoxir.M. 



usually unequal ; anthers fixed dorsally, 2-celled, de.hisi cnce introrse, 

 pollen subglobose reticulate. Disk fleshy. Ovary 3-celled ; style simple, 

 stigmas 3 linear revolute ; ovules 1 or more, attached to the inner angle 

 of each cell, amphitropous. Capsule 3-celled, loculicidally 3-valved ; valves 

 separating from the persistent axis; cells 1- or many-seeded. Seeds angled 

 or plano-convex, testa spongy sometimes winged, hiluin ventral, albumen 

 fleshy ; embryo axile, cotyledons subfoliaceous. DISTRIB. Chiefly arctic 

 and temp., especially W. American ; genera 17 ; species about 100. 

 AFFINITIES. With Convolvulacece. PROPERTIES unimportant. 



1. POLEMO'NIUM, L. JACOB'S-LADDER. 



Perennial herbs. Leaves alternate, pinnate. Flowers corymbose, usually 

 ebracteate. Calyx campanulate, 5-lobed. Corolla rotate ; lobes 5, obovate. 

 Stamens decliuate, inserted on the corolla-throat, filaments dilated and 

 hairy at the base. Disk cup-shaped, crenate. Ovary ovoid ; style filiform, 

 stigma 3-fid ; ovules many in each cell, 2-seriate. Capsule ovoid, 3-celled, 

 many-seeded, loculicidally 3-valved. Seeds ovoid, angled, with a short wing 

 or 0, testa thick, abounding in spiral vessels. DISTRIB. N. temp, and arctic 

 regions ; species about 12. ETYM. obscure. 



1. P. cseruleum, L. ; leaflets 6-12 pairs subsessile. Greek Valerian. 

 Copses and streams, apparently indigenous from Stafford and Derby north- 

 wards to the Cheviots, doubtfully elsewhere ; an outcast of gardens in 

 Scotland and Ireland; fl. June-July. RootstocJk short, creeping. Steins 

 1-3 ft., glabrous or pubescent and glandular above, angular, fistular, leafy. 

 Leaves 4-18 in.; petiole very slender, winged ; leaflets f-1^ in., quite entire, 

 ovate or oblong -lanceolate, acute, flowers many, drooping, ^1 in. diam., 

 blue or white. Calyx campanulate ; lobes oblong, acute. Corolla-lobes 

 spreading, subacute. Capsule erect, included in the calyx. Seeds compressed, 

 angular; testa costate and rugose, shortly winged. DISTRIB. Europe (Arctic) 

 to France and Italy, N. Asia, N.W. Himalaya, N. America. 



ORDER XLIX. CONVOLVULA'CEJE. 



Herbs or shrubs, usually twining (rarely trees); juice often milky. 

 Leaves alternate, in Cuscuta, exstipulate. Flowers in axillary or tef- 

 minal racemes cymes or heads, rarely solitary, often large, of all colours ; 

 pedicels often articulate with the peduncle and bracteate. Sepals 5, equal 

 or unequal, in 1-3 series, persistent. Corolla hypogynous, regular, 

 tubular bell- or funnel-shaped ; limb 5-lobed or -angled, plaited and 

 contorted in bud. Stamens 5, inserted on the corolla-tube, filaments 

 often unequal and dilated at the base ; anthers sagittate, basifixed, 

 2-celled, dehiscence introrse, often twisted after flowering, pollen angular 

 or spherical. Disk angular, hypogynous. Ovary of 2-4-connate carpels, 

 2-4-(rarely l)-celled ; style slender, 2-4-fid, stigmas capitate linear or 

 lamellar ; ovules 1 or 2 in each cell, erect from its base, 4 in the 1-celled 

 ovaries. Capsule 1-4-celled, 2-4-valved or bursting transversely at the 

 base. Seeds attached to the base of the central column, erect ; testa 

 coriaceous or membranous, often villous, albumen scanty mucilaginous 



