11. Ipomcea.] 



96. CONVOLVULACE.^. 



equal or unequal, often coriaceous or membranous, mostly short, some- 

 times accrescent in fruit and often becoming foliaceous papery or 

 brittle but not thick and fleshy nor enclosing- the fruit. Corolla 

 campanulate or funnel-shaped, entire or slightly lobed with the 

 vertical bands (which are the portions outermost in bud) usually 

 well marked by their slightly different texture or venation. Stamens 

 included, filaments often hairy or dilated at base, often unequal, 

 pollen spinulose or echinulate or {Merremia, etc., of some authors) 

 smooth or banded. Anthers ovate to linear, sometimes twisted. 

 Disc annular, often lobed. Ovary 2-, rarely 3- (Pharhitis) or 4- 

 (Batatas) celled, ovules -i. Stigma of two globose lobes. Capsule 

 coriaceous or membranous or brittle, usually •i-valved. Seeds 4 or 

 fewer. Cotyledons broad, plicate, often 2-lobed. 



Ipomoea of Linnaiis and in the Fl. Brit. India includes the groups sometimes 

 distinguished as genera under the names of Calonyetion, Mina, Quamoclit, Pharbitis, 

 Operculina, Aniseia and Merremia. The separation of the last two (by Hallier, f.) 

 appears to me especially artificial, and is based on the character of the extine of the 

 pollen (whether smooth or echinulate) unsupported by other characters (I find the 

 character of 2 or more lines, etc., in the bands unworkable), and separates obviously 

 allied species. Operculiiiahasheen separated by the supposedly circumsciss exo- 

 carp. This distinction is based on too few observations, as the exocarp of Ipomcea 

 (Operculina) furpethum sometimes splits longitudinally into 4 valves. Fharhitis 

 And Baiatas may be more natural, but these were not separated by Hallier. I there- 

 fore include all the genera Pharbitis, Batatas, Operculina, Aniseia and Merremia in 

 Ipomcea, and separate therefrom only Calonyction, Mina and Quamoclit, which are 

 ■easily distinguishable in our species. 



I. Ovary 2-celled (Spp. 1-24) :— 



A. Sepals green herbaceous, usually hairy (Spp. 1-7, see 



also 19 and 21) :— 



1, Outer 2-3 sepals much larger than the inner, accre- 



scent. (Small plants with undivided leaves under 



3" and peduncles often 1-fld. and 2-bracteate, fls. 



under 2") :— 

 Glabrescent. Sepals decurreut at base in fruit 



(Aniseia) ......... 1. unifiora. 



Hirsute. Sepals lanceolate. L. ovate-oblong . . 2. barlerioideg. 

 Villous. Sepals cordate or sagittate, not decurrent, 



leaves ovate conlate 3. eali/cina. 



2. Sepals equal or nearly so, scarcely accrescent. 



(Usually weak twiners with very hairy calyx) : — 

 a. Flowers pink in bracteate heads : — 



i. Leaves entire (see also I. pes-tiqridis, var.) : — 



Heads sessile or sub-sessile. Fls. small . . i. hispida. 

 Heads long-peduncled with a large 2-cuspidate 



bract 5. involucrata. 



ii. Leaves deeply lobed (entire in one var.). Hds. 



loug-petioled, many-bracteate . . . .6. pes-tigridis. 

 h. Fls. in lax persistently bracteate 2-3-fld. cymes :— 



Leaves white beneath, often 3-lobed . . . 7. pilosa. 



B. Sepals dry, membranous or somewhat fleshy with 



scarious margins, not hairy (hai 

 pubescent in 13 and 19). Spp. 8- 

 1. Leaves not deeply palmately 

 lobed: — 

 a. Small plants, never Avidely scandent. Fls. under 

 1", usually yellow or white :— 

 1. Sepals glabrous (Merremia) : — 



* Leaves longer than broad, usually ob- 

 long : — 

 Prostrate. L. sessile, often hastate, rarely 

 1". Fls, -3" 8. tridenfata. 



592 



i-y in 21, ciliate in 11, 

 -24:— 

 lobed or only 2-3- 



