Addisonia 33 



(Plate 137) 



RHABDADENIA CORALLICOLA 

 Little Allamanda 



Native of southern Florida 

 Family Apocynaceae Dogban:^ Family 



Rhabdadenia corallicola Small, Bull. N. Y. Bot. Gard. 3: 434. 1905. 



An erect or diffuse vShrub with a thick tough root and a woody 

 caudex. The stems are solitary or several together, up to four 

 feet tall, or rarely more elongate, and with the branches rarely 

 slightly twining at the tips, the twigs pubescent with fine brownish 

 hairs. The glabrous leaves are opposite, rather close together, 

 and commonly erect or ascending. The blades are elliptic or 

 elliptic-lanceolate, more or less revolute, obtuse but apparently 

 acute on account of the revolute margins, dark green and shining 

 above, paler, dull, and obscurely veined beneath, rounded or sub- 

 cordate at the base, short-petioled, the petioles leaving prominent 

 scars on the stem when the leaves fall. The racemes are lateral, 

 few-flowered, with small ovate to lanceolate bracts subtending the 

 pedicels, which vary from one half to three quarters of an inch in 

 length at maturity. The calyx is fleshy, glabrous; the five lobes 

 are deltoid-ovate or ovate-acuminate, fully one twelfth of an inch 

 long, persistent and with spreading tips at maturity. The corolla 

 is bright yellow, commonly nodding, with a short-cylindric tube, a 

 longer campanulate throat, and a spreading five-lobed limb fully 

 one inch wide ; the lobes are about as wide as long, inequilateral and 

 obliquely pointed. The five stamens are borne on the lower part 

 of the corolla; the filaments are adnate to the corolla-tube except a 

 short free part of each which is pubescent with long hairs. The 

 anthers are lanceolate-sagittate, about one sixth of an inch long, 

 each with two deflexed basal curved or hooked spur-like auricles 

 which are slightly shorter than the free part of the filament. The 

 gynoecium consists of two ovoid glabrous carpels seated in a five- 

 lobed disk, a filiform style, and an enlarged stigma which is dilated 

 into a reflexed membrane at the base. The follicles are paired, 

 three to five inches long, subulate, glabrous, bright green at matur- 

 ity, but brown after dehiscence. The seeds are numerous; the body 

 is narrowly fusiform, about one fourth of an inch long, narrowed 

 into a short neck or beak which is dissolved into numerous hairs. 



The plant here illustrated, although not particularly large- 

 flowered, is one of the conspicuous elements in the vegetation of 

 the pine woods south of Miami, Florida. Yellow and white pre- 

 dominate in the corollas of the dogbanes of southern Florida, but 



