LABIATAE 



357 



Kyrstenia Neck. (Eupaloiiutn Tourn. p.p.)- Compositae (2). 50 N. 

 Am. 



Labatia Sw. Sapotaceae (i). 6 trop. S. Am., W.L 



Labdanum, Cislits creticus L. , C. ladaniferus L. 



Labellum, Caniia, Muranfaceae, Orchidaceae, Stylidiaceae, Zingiberaceae. 



Labiatae (EP., J3H.}. Dicotyledons (Sympet. Tubiflorae; Lamiales 

 BH.}. 200 gen. 3000 sp., cosmop. ; chief centre the Medit. region. 

 Some small groups are localised in their distribution, e.g. II. in 

 Austr. and Tasmania, III. in India, Malaya, China, &c., VIII. in 

 Centr. Am., whereas the large ones, such as I. and IV., are cosmop. 

 Most L. are land-plants, and herbs or undershrubs, similar in habit 

 and structure. Stem usu. square, with decussate simple exstip. L, often 

 hairy and with epidermal glands secreting volatile oils, which give 

 char, scents to many. A few marsh-plants (Mentha, Lycopus, &c. ), 

 a few climbers (Stenogyne sp., Scutellaria. &c.), and a few small trees 

 (Hyptissp.). Manyxero. with reduced, sometimes infolded, 1., hairi- 

 ness, thick cuticles, &c. , e.g. Rosmarinus. 



The axis of the first order is not closed by a fl. but only those of 

 later orders; thus the primary form of the infl. is racemose, and a 

 simple raceme actually occurs in Scutellaria, &c. Usu. however a di- 

 chasial cyme, becoming cincinnal in its later branchings, occurs in the 

 axil of each 1. upon the upper part of 

 the main axis. In Teucrium, Nepeta 

 sp. , &c., the construction of this cyme 

 is easily seen ; but in most L. it is 

 closely 'condensed' into the axil, so 

 that all the fls. are sessile; but it is 

 easily seen that the central fl. opens 

 first and then those on either side of 

 it (see diagram). The two condensed 

 cymes at each node overlap the leaf- 

 axils and often form what looks like v \ c T 



, , c a ... . a . r * loral diagram of Lamuim album 



a whorl of Ms. ; this infl. IS often with indication of dich. double 



called a verticillaster or false whorl. cincinnus at the sides. (After 



Fl. 5 or gynodioec., -|-,hypO!J., Eichler.) The asterisk repre- 



J r sents the missing posterior sta 



5-merous with suppression in some 



whorls. Usu. formula K (5), C (5), A 4, G (2). K tubular, bell- or 

 funnel-shaped, sometimes 2-lipped, persistent in fr. ; C usu. 2-lipped 

 with no clear indication of the individual petals; A 4, didynamous, or 

 of nearly equal length, sometimes 2, epipet. with intr. anthers. 

 G on a nectariferous disc (often developed on anterior side only), 

 of (2) cpls. placed antero-post. Early in development a constriction 

 appears in the ovary in the antero-post. line, dividing each cpl. into 

 2 loculi, so that the ovary becomes 4-loc. as it matures. Each of the 

 4 portions is nearly independent of the rest, and the style springs 

 between them from the base of the ovary (i.e. is gynobastc) ; stigma 

 2-lobed. Placentae axile, each with i basal erect anatr. ovule with 

 ventral raphe. Fr. usu. a group of 4 achenes or nutlets, each 

 containing one seed ; sometimes a drupe. Seed with no enclosp. 

 or very little; the radicle of the embryo points downwards (cf. 

 Boraginaceae). 



