Notes
1) A. stachyosporus and A. undulatus
A. stachyosporus and A. undulatus were held to be synonyms, but, Les, Moody and Jacobs (2005) state:
Bruggen (1985) treated A. undulatus
and the narrower-leaved A. stachyosporus as conspecific,
assuming that wide variability of leaf morphology
existed in A. undulatus. This conclusion would be supported
by our cpDNA sequences, which were identical
in the two taxa (Fig. 4); however, we found their ITS
sequences to differ by seven substitutions (Fig. 3), a
level comparable to (or exceeding) the degree of ITS
divergence that we observed between a number of other
Aponogeton species. The ITS data would indicate that
the distinctness of these two taxa should be reconsidered.
Given that there are lessor differences between other different species of
Aponogeton it would seem prudent to refer to
A. stachysporus and
A. undulatus are different species.
2) With the publication in 2016 of
A. wolfganensis there is a new key to Indian species of
Aponogeton
Key to the species of Aponogeton from India
Key to the Indian species of Aponogeton based on number of seeds per fruit and embryo characters is provided below
and the morphological features of embryo of Indian species of
Aponogeton and
A. jacobsenii from Sri Lanka are
depicted in Table 2 and shown in Fig. 3.
1. Seeds 4–8 per fruit, embryo elliptic, small, 3–4 × 2–2.5 mm ...................... 2
– Seeds 1–2 per fruit, embryo elliptic or globose or trapezoid, large ............... 3
2. Embryo 3 × 2 mm .................................................................. A. lakhonensis
– Embryo 4 × 2.5 mm ................................................................. A. natans
3. Embryo without appendages ........................................................ 4
– Embryo with appendages ............................................................ 8
4. Plumule attached at side of the embryo at the middle ............................. A. wolfgangianus
– Plumule attached at side of the embryo at the base ................................ 5
5. Embryo elliptic, cotyledon non-grooved, pointed .................................. A. bruggenii
– Embryo elliptic, grooved, rounded ................................................. 6
6. Embryo elliptic, cotyledon with narrow dorsal grove .............................. A. satarensis
– Embryo elliptic, cotyledon with broad concave groove .............................. 7
7. Embryo 10–12 × 4–5 mm ............................................................ A. crispus
– Embryo 5 × 2 mm ................................................................... A. undulatus
8. Embryo obovate, tuberous, crowned with 3–4 tortuous appendage .................... A. appendiculatus
– Embryo globular, tuberous, 16–20 (5–6) appendages all around ...................... A. nateshii
