Orlovich, Drinnan & Ladiges, Floral development in the Metrosideros group 
697 
Fig. 5. (left) Horal development in Lophostemon suaveolens. a, very small flower primordium. Two 
bracts have been removed to show the first sepal primordium (K) (x 170); b, flower bud with two 
sepal primordia (Kl-2) (x 250); c, flower bud with tliree sepal primordia (Kl-3) (x 250); d, flower bud 
with five sepal primordia arranged in a spiral pattern. Two sepals have been removed (Kl-2) to show 
the other three sepal primordia (K3-5) and the first petal primordium (P). The floral apex is beginning 
to invaginate (x 140); e, half flower bud with two sepals removed to show developing petal primordia 
(P). K - sepal (x 135); t, flower bud with three sepal and four petal primordia. A small PSB is visible 
directly in front of each petal primordium (arrows) (x 90); g, tlrree petal primordia (P) with a PSB in 
front of each one. Tl-iere is a distinct difference in size between adjacent petal primordia (x 190); 
h, two petal primordia with a PSB in front of each one. A vertical groove is visible on each PSB at this 
stage (arrows) (x 160); i, two petal primordia with a PSB in front of each one. Stamen primordia are 
visible along the upper edge of each PSB (x 90); j, part of a flower bud after initiation of most stamen 
primordia. Two petals have been removed (P). The oldest stamens are those situated at the upper 
central region of the PSB. There are small stamen primordia at the edges of each PSB (x 120); 
k, mature flower bud viewed from the outside of the flower shortly before anthesis. Sepals (K) and 
petals (P) have been removed to expose a stamen fascicle. The fascicle is bifid, the central split (arrow) 
corresponding in position to the notch on the PSB in younger buds (x 40). (from DAO 233). 
Fig. 6. Lophostemon lactiflmis. a, mature half flower (x 18.1); b, stamen fascicle drawn from the 
back. This fascicle is not bifid (x 21). (from UNSW 4016). 
