AMAKANTHACEAE 395 



axillary clusters. Sepals 5, lanuginous, 3-nerved or nerveless. Stamens 5 : filaments 

 united intp a short cup at the base, without staminodia between the 1-celled anthers. 

 Ovary 1-celled, flattened : style short : stigma notched. Ovule solitary. Utricle mem- 

 branous, indehiscent. Seed lenticular, shining. 



Bracts ovate or ovate-lanceolate : sepals 3-nerved. 1. G. lanuginosus. 



Bracts suborbicular : sepals nerveless. 2. G. Sheldonii. 



1. G-ossypianthus lanuginosus (Poir. ) Moq. Foliage woolly. Stems branched at 

 the base, the branches spreading or prostrate, 5-30 cm. long, forking : leaves various ; 

 basal prostrate, the blades spatulate or linear-spatulate, 2-7 cm. long, acute or obtusish : 

 stem-leaves opposite ; blades orbicular-obovate, ovate or lanceolate, 4-12 mm. long, acute 

 or obtuse, sessile, often reflexed : clusters 5-10 mm. thick, more or less conspicuously 

 woolly : bracts ovate to ovate-lanceolate, about as long as the calyx : sepals densely 

 woolly, 2.5-3 mm. long, narrowly lanceolate, acuminate, 3-nerved, scarious-margined : 

 utricle included. 



On dry plains or prairies, the Indian Territory to Texas and adjacent Mexico. Summer and fall. 



2. Gossypianthus Sheldonii (Uline & Bray) Small. Similar to G. lanuginosus in 

 habit, but much stouter and with more densely woolly foliage. Leaf-blades, at least some of 

 them, broadly spatulate, leathery : bracts suborbicular : sepals 5-6.5 mm. long, lanceolate. 



In dry soil, near Cash Creek, Indian Territory. Summer. 



8. ALTERNANTHERA Forsk. 



Annual or perennial herbs, with decumbent or prostrate stems. Leaves opposite : 

 blades narrow or broad, entire or nearly so, sessile or petioled. Flowers perfect, in sessile 

 or ped uncled head-like spikes ; these usually white or silvery. Sepals 5, unequal, 2 more 

 concave than the rest. Stamens" 5, the filaments partially united into a cup-like tube : 

 staminodia surpassing the filaments and 1-celled anthers or shorter. Ovary 1-celled : style 

 variable in length : stigma capitate. Ovule solitary. Utricle flattened, indehiscent. 

 Seeds lenticular, smooth. The plants flower from spring to fall, and also in winter in the 

 southern part of our range. Our species are perennials. 



Staminodia shorter than the filaments. 



Stems pubescent : sepals awn-tipped : staminodia entire or nearly so. 1. A. repens. 



Stems glabrous or nearly so: sepals not awn-tipped: staminodia copiously 



toothed. 2. A. paronychioides. 



Staminodia as long as the filaments or surpassing them. 



Spikes sessile or nearly so : calyx sessile : sepals unequal in length. 3. A. maritima. 



Spikes long-peduncled : calyx pedicelled : sepals, at least 4, nearly equal. 

 Peduncles shorter than the leaves : sepals glabrous. 



Leaf-blades linear to linear-oblanceolate, many times longer than broad : 



sepals 5-6 mm. long. 4. A. philoxeroides. 



Leaf-blades broadly ovate, a little longer than broad : sepals 3-3.5 mm. 



long. 5. A. Moquinii. 



Peduncles surpassing the leaves : sepals pubescent. 



Stems minutely pubescent with appressed hairs : anthers on filaments 



equalling them in length. 6. A. Floridana. 



Stems pubescent with ascending or spreading hairs : anthers sessile or 



nearly so. 7. A. Brasiliana. 



1. Alternanthera repens (L. ) Kuntze. Plants pubescent. Stems branched at the 

 base, the branches prostrate, 1-5 dm. long, forking, somewhat hirsute : leaves somewhat 

 clustered ; blades spatulate, oval, ovate or suborbicular, 8-20 mm. long, often abruptly 

 pointed or rather obtuse, narrowed into short petioles : flower-clusters axillary : sepals un- 

 equal, lanceolate, awn-tipped, the shorter one copiously pubescent with barbed hairs, all 

 1-nerved : staminodia nearly as long as the filaments, entire, at least above : utricle ovoid, 

 included, furnished with a sharp wing below the apex. 



In waste places and cultivated grounds, South Carolina to California and South America. 



2. Alternanthera paronychioides St. Hil. Plants glabrate. Stems branched at 

 the base, the branches prostrate or creeping, 1-4 dm. long, freely branching, glabrous or 

 glabrate : leaf -blades spatulate or elliptic to oval, 0.5-2 cm. long, acute or obtuse, entire, 

 decidedly petioled : flower-clusters axillary, 1 cm. thick or smaller : bracts lanceolate, 

 acuminate : sepals pearly white, nearly equal, pubescent, not awn-tipped, merely acute : 

 staminodia broad, about as long as the filaments, toothed to the apex : utricle flattened, 

 obcordate. 



In dry soil, North Carolina to Florida, Texas and tropical America. 



3. Alternanthera maritima St. Hil. Plants glabrous, fleshy. Stems or the 

 branches prostrate, 2-8 dm. long, angled, branched : leaf-blades leathery, cuneate to 



