A Second Hawaiian Species of Alectryon (Sapindaceae) : 
Hawaiian Plant Studies 17 1 
Harold St. John 2 and Lafayette Frederick 
The GENUS Alectryon has been known in the 
Hawaiian Islands by a single species, A. macro- 
coccus Radik. It was first collected by Hille- 
brand, but, though he found it on two different 
islands, Molokai and Oahu, he never succeeded 
in assembling complete material. The binomial 
was published in 1890, based solely on Hille- 
brand’s incomplete collections and data. Since 
that time, successive botanists, Rock, Forbes, 
Degener, and others, have found new localities 
for the species; it is now known on Kauai, Oahu, 
Molokai, and Maui. Nevertheless, Alectryon is 
still considered a rare tree. On Kauai it was dis- 
covered by Gay, and by Lydgate in Olokele 
Valley, apparently early in the 20th century, 
but it has not been found there since. On Molo- 
kai it is apparently extinct at the type locality, 
though Degener found another station only a 
mile or two away at Puu Makaliilii, where in 
1928 there were two dying trees. On Maui it 
was known from the rich, dry forest at Auahi 
on Haleakala, where Rock in 1910 found 40 
trees. Since Rock’s time this rich area has been 
deforested by cattle grazing. Another station 
was found by Forbes in Olowalu Valley, west 
Maui, in 1920, but no one has found Alectryon 
there since. On Oahu it is now known to ex- 
tend, in the Waianae Mountains, from Pahole 
Gulch to Ekahanui Gulch, or nearly the full 
1 This is the seventeenth of a series of papers de- 
signed to present descriptions, revisions, and records 
of Hawaiian plants. The preceding papers have been 
published in Bernice P. Bishop Mus., Occas. Papers 
10(4), 1933; 10(12), 1934; 11(14), 1935; 12(8), 
1936; 14(8), 1938; 15(1), 1939; 15(2), 1939; 
15(22), 1940; 15(28), 1940; 17(12), 1943; Calif. 
Acad. Sci., Proc. IV, 25(16), 1946; Torrey Bot. Club, 
Bui. 72:22-30, 1945; Lloydia 7:265-274, 1944; 
Pacific Sci. 1: 5-20, 1947; Brittonia 6(4) : 431-449, 
1949; Gray Herb. Contrib. 165: 39—42, pi. 3, 1947. 
2 Chairman, Department of Botany, University of 
Hawaii. Manuscript received June 28, 1948. 
length of that mountain range. Yet, even on 
Oahu, the trees are few and remote and the 
discovery of one is a noteworthy event on a 
day’s exploration. Most unusual is the large 
single or double fruit with its woody pericarp 
and abundant, juicy, scarlet, edible aril, some- 
what resembling those of the related "litchi.” 
It is now evident that the genus contains 
more than one Hawaiian species and that the 
original Alectryon macrococcus was described 
from material assembled from two islands and 
representing two species. To straighten out 
this confusion it has been necessary to select a 
lectotype for the older species and describe the 
other as a new species. 
SAPINDACEAE 
Alectryon (§Mahoe) Mahoe St. John & Fred- 
erick, sp. nov. 
Figs. 1, 2. 
Diagnosis Typi: Arbor 7 m. alta, ramis fusci- 
rubri-brunneis, glabratis, cicatricibus 4.5-6 
mm. latis scutiformibus pallide brunneis fasci- 
culis 3, ramulis foliosis 4-6 mm. diametro tere- 
tibus adpressi-puberulis, internodis 5-35 mm. 
longis, foliis 27-42 cm. longis pari-pinnatis, 
petiolis 6-12 cm. longis adpressi-puberulis, 
foliolis 2-3-jugis, petiolulis 8-15 mm. longis basi 
inflata adpressi-puberulis, foliolis 10.5-21 cm. 
longis 5-10 cm. latis, plerumque ellipticis vel 
minime lanceo- vel oblanceo-ellipticis rare ovali- 
bus plerumque plusminusve asymmetricibus, 
apice obtusi, basi rotundata vel abrupte subcun- 
eata, laminis rigide crasse chartaceis fusci-viridi- 
bus glabris margine integri plani vel undulati, 
infra pagina intervallis glabris nervis salientibus 
adpressi-puberulentis, venulis saliente reticulatis, 
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