126 AMAKANTHACEAE. 



1. Centrostachys indica (L.) Standley, Journ. Wash. Acad. Sei. 5: 75. 1915. 



Achyranthes aspera indica L. Sp. PI. 204. 1753. 

 Acni/rantlies indica, Mill. Gard. Diet. ed. 8, no. 2. 1768. 

 Acli'iirantlies obtusifolia Lam. Encycl. 1: 545. 1785. 

 Acliyrantlies aspera obtusifolia Griseb. Fl. Br. W. I. 62. 1859. 



Herbaceous, erect or ascending, simple or branched, 6-12 dm. high, rather 

 densely pubescent above. Leaves suborbicular or obovate-orbicular, pubescent, 

 2-5 cm. long, abruptly short-tipped at the apex, narrowed or cuneate at the 

 base, pinnately veined, the slender petioles 1-3 em. long ; spikes very slender, 

 2-6 dm. long, densely flowered above, the lower flowers scattered ; flowers 

 about 4 mm. long ; bracts subulate, horny, glabrous, a little shorter than the 

 calyx, deflexed ; sepals acuminate. 



A weed in waste places and cultivated soils, throughout the archipelago from 

 Abaco south to Acklin's Island : a weed in tropical and subtropical regions. 

 BLUNT-LEAVED CEXTROSTACHYS. 



4. ACHYRANTHES L. Sp. PI. 204. 1753. 



Decumbent or prostrate herbs. Leaves opposite, entire or nearly so. 

 Flowers perfect, in sessile or peduncled, head-like, usually white or silvery 

 spikes. Sepals 5, unequal. Stamens 5, the filaments partially united into a 

 cup-like tube ; staminodia surpassing the filaments and 2-eelled anthers, or 

 shorter. Ovary 1-eelled ; stigma capitate. Ovule solitary. Utricle flattened, 

 indehiscent. Seeds lenticular, smooth. [Greek, straw-flower.] Forty species 

 or more, mostly of tropical distribution. Type species: AcliyrantJies repens L. 



Plants succulent: leaves sessile. 1. A. maritima. 

 Plants not succulent. 



Sepals merely acute. -. A. polygonoides. 



Sepals spinulose-tipped. 3. A. repens. 



1. Achyranthes maritima (St. Hil.) Standley, Journ. Wash. Acad. Sci. 5: 



74. 1915. 



Alternanthera maritima, St. Hil. Voy. Bras. 2: 437. 1833. 



Plants glabrous, fleshy. Stems or the branches prostrate, 2-8 dm. long, 

 angled, branched; leaves leathery, cuueate to oblong or elliptic, 1.5-6 cm. long, 

 obtuse, commonly mucronate, entire, sessile or somewhat petioled ; spikes dull 

 straw-colored, 6-12 mm. long, sessile, leaving a conspicuous sear when detached; 

 bracts ovate, keeled ; calyx ^ longer than the bracts ; sepals rigid, ovate, acute 

 and slightly awn-tipped, usually 5-nerved, glabrous; staminodia longer than 

 the filaments, cleft or lacerate at the tip. 



Maritime sands at the wave line. Great Bahama, Frozen Cay, South Birninl, 

 Little Mangrove Cay. New Providence and Cat Island : Bermuda ; Florida : Cuba : 

 Guiana to Brazil west roast of Africa. Referred to by Dolley and by Herrick as 

 Oompltrena sp. BEACH ACHYRAXTHES. 



2. Achyranthes polygonoides (L.) Lam. Eneycl. 1: 547. 1785. 



Gomplirena polygonoides L. Sp. PI. 225. 1753. 



Alternanthera paronycnioides St. Hil. Voy. Bras. 2: 439. 1833. 



Glabrous or sparingly pilose, branched, the branches procumbent or creep- 

 ing, 1-4 dm. long. Leaves spatulate to elliptic, 2 em. long or less, obscurely 

 veined, acute or obtuse at the apex, narrowed at the base, the petioles 5-10 mm. 

 long; flowers in dense sessile globose axillary heads 8-12 mm. in diameter; 

 sepals bright white, shining, lanceolate, acute, slightly unequal, about 3 mm. 



