1:38 FLORA OF JAMAICA Alternantliera 



8. ALTERNANTHERA Forsk. 



Herbs, often somewhat woody below, usually prostrate or 

 decumbent. Leaves opposite. Flowers small, hermaphrodite, 

 capitate. Heads sessile (in Jamaican species), axillary, solitary, 

 or 2 or 3 clustered. Bract flat, shorter than exterior lateral 

 perianth-segments, bracteoles concave. Perianth with 5 unequal 

 segments, two exterior flattened, median flattened, shorter, two 

 lateral interior concave, still shorter. Stamens 35 ; filaments 

 united into a short cup at base, with alternating staminodes ; 

 anthers 1 -celled. Ovary with one ovule pendulous at the end of 

 a long stalk. Utricle compressed, roundish to obcordate. Seed 

 with annular embryo. 



Species 70, natives of tropics and subtropics, especially of 

 America. 



Leaves of a pair very unequal. 



Leaves obovate-rhomboid, unequal-sided. Exterior 

 perianth-segments villose at base only or 



glabrate 1. A.repens. 



Leaves mostly elliptical, equal-sided. Exterior 



perianth-segments villose 2. A. par vi folia. 



Leaves of a pair, more or less equal. 



Perianth mucronate or spiny 3. A. ficoidea. 



Perianth not mucronate nor spiny, though some- 

 times slightly mucronulate. 

 Perianth 2 mm. 1., exterior segments 1-ribbed, 



glabrous. Utricle longer than perianth 4. A. sessilis. 



Perianth 4 mm. 1., exterior segments 3-ribbed 



and hirsute below 5. A. imronycMoides.. 



1. A. pepens Kunfze Bev. ii. 540 (1891); leaves obovate- 

 rhomboid or obovate-elliptical, unequal-sided, obtuse, one of a pair 

 larger than the other ; two exterior segments of perianth strongly 

 acuminate-spiny, with three strong nerves, and short hairs near 

 base or glabrate ; hairs minutely barbed at apex. -TJrh. Symh. 

 Ant. iv. 221 (in part). A. Achyrantha Moq. in DC. Prodr. xiii. 

 pt. 2, 358 (1849) ,; Griseb. Fl. Br. W. hid. 67 (in part). Achy- 

 ranthes repens L. Sjp. PI. 205 (1753). Illecebrum Achyrantha 

 L. % PI. ed. 2, ^99 (1762). 



A prostrate weed on sides of streets, Spanish Town, Harris & Britton !' 

 Fl. Jam. 10,517. Florida, Central and S. America, west trop. Africa. 



Stem pubescent-villose. Leaves mucronate, with a few hairs near the 

 base or glabrate, larger 1-5-2 -5 cm. 1., 1-1*5 cm. br., smaller -7- "8 cm. 1. 

 Heads 7-12 mm. 1. Bracts glabrous, lanceolate with spiny apex, a little 

 shorter than exterior perianth-segments and a little longer than bracteoles. 

 Flowers straw-coloured. Perianth-segments, two exterior 4-5 mm. 1., 

 lanceolate, median elliptical, obtuse, mucronate, with short hairs below, 

 about 3 mm. 1. ; interior 2*5 mm. 1., bearded just above the middle but 

 not to the apex. Staynens 5, about 1 mm. 1. ; staminodes in form of 

 short teeth; cup '25 mm. 1. Utricle 1*5 mm. 1., roundish, somewhat 

 truncate at apex. Seed 1*3 mm. 1., round, compressed. 



