ACANTHACEAE 9 



Acajou (W. I.), Guarea trichilioides L. 



Acaju, Cashew, Anacardium occidental L. 



Acalypha L. Euphorbiaceae (A. II. 2). 300 trop. , S. Afr. Anther 

 lobes twisted ; stigmas branched. Several cult, for varieg. 1. 



Acampe Lindl. Orchidaceae (n. 16). 12 Indomal., China, (Afr. BH.). 



Acamptocladus Nash (Eragrostis Host, p^p.). Gramin. (n). i S.W. 

 U.S. 



Acamptopappus A. Gray (AplopappusCa.ss.J3H.). Comp. (3). 2 N. Am. 



Acanthaceae (EP., BH.). Dicots. (Sympet. Tubiflorae). 140 gen., 

 2000 sp., esp. trop. but also Medit., U.S., Austr. 4 chief centres 

 of distr. : Indomalaya, char, by Strobilanthes and Andrographidae, 

 Afr. (Thunbergia and Barleria), Braz. (Mendoncia and Ruellia), and 

 Centr. Am. (Aphelandreae and Odontonema). Many biological types 

 climbing plants, xerophytes, marsh plants, &c. and much variety 

 in habit. Very many in. damp places in trop. forests. Trees are rare ; 

 most are shrubs or herbs with opp., usu. decussate and entire, exstip. 1., 

 usu. thin. Cystoliths, visible as streaks or protuberances, are usu. 

 common on 1. and stems. Infl. most commonly a dich. cyme, in its 

 ultimate branchings tending to monoch., and frequently condensed in 

 the leaf-axils as in Labiatae. Racemose infls. also occur, and sol. fl. 

 are common. Bracts and bracteoles usu. present, o'ften coloured; the 

 latter frequently large, enclosing the fl. 



Fl. $, hypog., zygom., usu. with nectariferous disc below ov. 

 K (5 4), C (54), commonly two-lipped (upper lip sometimes not 

 developed, e.g. in Acanthus). A rarely 5, usu. 4 or 2 epipet., usu. 

 exserted ; i 3 stds. frequently present ; anthers often with one lobe 

 smaller than the other, or abortive; connective often long (rf. Salvia). 

 The pollen exhibits great variety of patterns (see Nat. Pfl.); these 

 are generally constant in the genus, and may be used in classification. 

 G (2), 2-loc. with axile plac. each with 2 oo usu. anatr. ov. in two 

 rows. Style usu. long with two stigmas, the post, often smaller. The 

 general arrangement of the fl. for visits of insects, protection of pollen, 

 &c. is like Labiatae or Scrophulariaceae. 



Fr. a bi-loc. caps, (with few exceptions), usu.. stalked, loculic. 

 to the very base. Seeds usu. exalb. Their modes of distribution are 

 interesting (see Nat. Pji.). The capsules of iv explode and the 

 seeds are thrown out, largely by the aid of peculiar hook-like out- 

 growths from their stalks (retinacula or jacnlators). Many have 

 superficial scales and hairs which on wetting become mucilaginous 

 (cf. Linum, Collomia), e.g. Crossandra, Ruellia, Blepharis. 

 Classification and chief genera (after Lindau) : 



I. NELSONIOIDEAE (Ovules oo ; jaculators papilla- 



shaped) : Ebermaiera, Nelsonia. 



II. MENDONCIOIDEAE (Ov. 4, seeds not more than 2. 



Drupe; no jac.): Mendoncia. 



III. THUVBERGIOIDEAE (Ov. 4 . Capsule; jac. papilla- 



like): Thunbergia. 



IV. ACANTHI01DEAE (Ov. 2 co . Capsule; jac. hook- 



shaped) : 



A. Contortae (cor. conv., or never ascendingly imbr.): 

 Strobilanthes, Ruellia, Eranthemum, Barleria. 



